Mahonia japonica, Narrow-leaved Mahonia japonica, and Flat-leaved Mahonia japonica all belong to the genus Berberis in the family Berberidaceae. They have odd-pinnately compound leaves with coarse, needle-like serrations and are frequently cultivated as ornamental plants due to their ease of growth. However, few people may be able to properly distinguish between the three species. Narrow-leaved Mahonia japonica and Flat-leaved Mahonia japonica are particularly often confused. The three species can be correctly distinguished by checking not only the size of the leaves but also the leaflets and the number of serrations on the leaflets. This article will explain the classification and morphology of the genus Berberis.

What are Mahonia japonica, Narrow-leaved Mahonia japonica, and Flat-leaved Mahonia japonica?

Berberis japonica (synonym: Mahonia japonica), also known as holly maize, is an evergreen shrub native to the Himalayas, China, and Taiwan. It is believed to have been introduced to Japan in the early Edo period and is planted in parks and gardens, and sometimes escapes into woodlands in plains.

Narrow-leaved holly mauve, also known as Berberis fortunei (synonym: Mahonia fortunei), is native to China and was introduced to Japan in the early Meiji period. It is an evergreen shrub that is commonly planted in parks and private gardens.

Narihirahiira Nandina (Berberis eurybracteata subsp. eurybracteata, synonyms: Mahonia eurybracteata, Mahonia confusa) is also known as Mahonia confusa. Native to China, it is an evergreen shrub that has recently become popular in gardens and parks in Japan. In horticulture, it is sold under the older scientific names Mahonia confusa and Mahonia confusa.

All of these plants belong to the genus Berberis in the family Berberidaceae, and they share the characteristics of having odd-pinnately compound leaves with needle-like, coarse serrations, producing yellow flowers, and bearing spherical berries that ripen to a powdery white, dark purple color. In older classifications, they were sometimes included in the genus Mahonia.

[Seed Plant Encyclopedia #123] What are the species of the Berberidaceae family? Photo list

Berberidaceae are perennial herbs or shrubs. Their leaves are alternate and can be simple or compound. The sepals are arranged in groups of three in 3-4 whorls, or two in 4 whorls; the outer 1-2 whorls are smaller and fall off quickly during flowering, while the inner 2 whorls are larger and petal-like. The petals are 2 or...

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The Japanese name comes from the fact that its needle-like, coarse serrations resemble those of holly, and its odd-pinnately compound leaves resemble those of nandina, which is taxonomically close.

Because it is evergreen, it is tolerant of shade and is less susceptible to pest damage. Furthermore, its leaves turn red in winter when exposed to sunlight, making it visually appealing, and it is frequently seen planted in parks and gardens.

The flowers of Mahonia are mainly pollinated by honeybees, and an interesting phenomenon has been observed in which the stamens move in a reflex action when they touch them while trying to collect nectar (Tanaka and Hirano, 2000).

Furthermore, the fruit is dispersed by birds, and in Japan, it has been observed that brown-eared bulbuls eat the fruit (Fujita and Shinohara, 2001).

However, the three species are often confused, and especially with the recent introduction of Mahonia japonica, few people can correctly distinguish between Narrow-leaved Mahonia and Flat-leaved Mahonia.

What are the differences between Mahonia japonica, Narrow-leaved Mahonia japonica, and Flat-leaved Mahonia japonica?

The three species can be distinguished relatively easily by their leaves (Wu et al., 2011; Kanagawa Prefectural Flora Survey Association, 2018; Hayashi, 2019).

First, while the leaflets of Mahonia japonica are thick, those of Mahonia japonica var. japonica and Mahonia japonica var. japonica var. japonica are narrow. This is immediately obvious and can be predicted from the Japanese name "Nahonia japonica var. japonica var. japonica".

Furthermore, while Mahonia japonica flowers from March to April and its fruit ripens in the autumn, Narrow-leaved Mahonia japonica and Flat-leaved Mahonia japonica flower from September to November and their fruit ripens in the spring.

The slightly tricky ones are the narrow-leaved holly mahonia and the flat-leaved holly mahonia. They look quite similar from a distance.

However, there is a difference between the two: Narrow-leaved holly mahonia has 3 to 4 pairs of leaflets with many sharp serrations, while flat-leaved holly mahonia has 5 to 10 pairs of leaflets with fewer blunt serrations.

While it's true that in Narrow-leaved Holly Mahonia, the flower stalk is almost the same length as the bract, and in Flat-leaved Holly Mahonia, the flower stalk is much longer than the bracts, these differences are difficult to confirm outside of the flowering season.

Although it's not mentioned in the botanical guide, my understanding is that in Narrow-leaved Holly Mahonia, the petioles (the parts connecting the leaflets) are green, while in Flat-leaved Holly Mahonia, they are purple.

Are there any other similar types?

While the three species mentioned above are generally cultivated in Japan, there are also suggestions of a horticultural variety that is a hybrid with Berberis lomariifolia, which is native to China, and has a slightly more upright inflorescence that blooms earlier than Mahonia japonica (January-February). I am not very familiar with this particular variety.

Nandina is the species from which the name "holly nandina" originates, but its fruit is red and its leaves do not have serrations.

While holly is also a species from which the name "holly-leafed mahonia" originates, it belongs to a completely different classification and has simple leaves rather than odd-pinnately compound leaves. Please see the separate article for more details.

What are the differences between holly (Ilex crenata) and holly osmanthus? What are the differences between Ilex crenata, European holly, and holly mauve? We'll explain how to distinguish between similar species! Are the two types of leaves a result of evolution?

Both holly (Ilex crenata) and holly osmanthus belong to the Oleaceae family and Osmanthus genus, and can be seen cultivated even in urban areas. Young holly trees are also frequently seen in forests. Morphologically, both have serrated leaves, which is why these two species are often confused...

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References

Fujita, Kaoru & Shinohara, Yukiko. 2001. Dispersal of planted trees into natural forests by birds and mammals. Strix 19: 103-113. ISSN: 0910-6901, https://mobile.wbsj.org/nature/public/strix/19/Strix19_12.pdf

Hayashi, Masayuki. 2019. Tree Leaves: Expanded and Revised Edition - Identifying 1300 Species Through Real-Life Scans. Yama-kei Publishers, Tokyo. 824pp. ISBN: 9784635070447

Kanagawa Prefecture Flora Survey Association. 2018. Kanagawa Prefecture Flora 2018 (Electronic Edition). Kanagawa Prefecture Flora Survey Association, Odawara. 1803pp. ISBN: 9784991053726

Tanaka, Hajime & Hirano, Takahisa. 2000. The Face of Flowers: Wisdom for Bearing Fruit. Yama-kei Publishers, Tokyo. 191pp. ISBN: 9784635063043

Wu, ZY, Raven, PH, & Hong, DY (Eds.). 2011. Flora of China (Vol. 19 Cucurbitaceae through Valerianaceae, with Annonaceae and Berberidaceae). Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis. ISBN: 9781935641049

Both holly (Ilex crenata) and holly osmanthus belong to the Oleaceae family and are commonly cultivated in urban areas. Young holly trees are also frequently seen in forests. Morphologically, both have serrated leaves, which often leads to confusion between the two species. Furthermore, there are many other plants with "holly" in their name, such as Ilex crenata, Ilex integra, and Nandina domestica, which are also frequently confused. However, careful observation of the leaves, flowers, and fruits reveals clear differences. Interestingly, both holly and Ilex crenata have been found to have both serrated and entire leaves, which is thought to be related to the feeding habits of herbivorous mammals such as Japanese deer. This article will explain the classification and ecology of species that closely resemble holly.

What are holly (Ilex crenata) and holly osmanthus?

Osmanthus heterophyllus, also known as tiger holly, is a small evergreen tree distributed in Honshu (west of the Kanto region), Shikoku, and Kyushu in Japan, growing on the slopes of slightly dry hills. It is also commonly planted in gardens as an ornamental plant, and escaped cultivation is common.

Osmanthus x fortunei, also known as holly osmanthus, is a presumed hybrid of holly and Osmanthus asiaticus. It is cultivated in parks, streets, and gardens, and sometimes escapes cultivation.

Both belong to the genus Osmanthus in the family Oleaceae, and can be seen being cultivated even in urban areas. As for holly, young trees can often be seen in forests.

Morphologically, they share common characteristics such as serrated leaves, a corolla with a tube and four lobes, and a drupe fruit (Kanagawa Prefecture Flora Survey Association, 2018).

Therefore, these two species are often confused. Moreover, there are many other plants with "holly" in their name, such as Ilex crenata, Ilex integra, and Nandina domestica, and these are also frequently confused.

What is the difference between holly and holly osmanthus?

Holly and holly olive can be distinguished by the shape of their leaves (Hayashi, 2019).

Specifically, in the leaves with serrations, holly has 3 to 5 pairs of larger serrations, while holly osmanthus has 6 to 10 pairs of finer serrations.

This can be understood by considering that Osmanthus heterophyllus is a hybrid of Osmanthus fragrans, which has coarsely serrated leaves, and Osmanthus fragrans, which has finely serrated leaves.

Also, although it's not often pointed out, there seem to be differences in the shape of the flowers as well.

In holly, the corolla lobes are curved backward and the stamens clearly protrude from the corolla, whereas in holly osmanthus, the corolla lobes are flat and the stamens are usually contained within the corolla.

This, too, can be considered a result of the holly osmanthus inheriting elements of the silver osmanthus flower.

What are the differences between Japanese holly (Ilex crenata), Japanese holly (Ilex rotunda), and European holly (Ilex serrata)?

Other species with names similar to holly include Japanese holly (Ilex crenata) and European holly (Ilex rotunda).

Ilex cornuta, also known as Japanese holly (Ilex cornuta), has the standard Japanese name Yabane-hiiragimochi (arrow feather holly), and is also called Hiiragimodoki (false holly) or Shina-hiiragi (Chinese holly). Native to China and the Korean Peninsula, it is an evergreen shrub sometimes cultivated as an ornamental plant in gardens, hedges, or pots.

European holly (Ilex aquifolium), also known as Christmas holly, is an evergreen shrub native to Europe and West Asia, cultivated for ornamental purposes. It is used in Christmas decorations.

These species are named after the fact that their leaves have sharp serrations, similar to holly, and they are also evergreen trees, which likely contributes to the confusion.

However, their classifications are quite different to begin with. As mentioned above, Japanese holly belongs to the Oleaceae family, while Japanese holly and European holly belong to the Aquifoliaceae family.

It's common for flowers and fruits to differ significantly between different plant families.

Regarding the flowers, Japanese holly (Ilex crenata) is dioecious, meaning that each flower has either stamens or pistils, whereas Japanese holly (Ilex crenata) and European holly (Ilex rotunda) are monoecious, meaning that each flower has both stamens and pistils. Additionally, Japanese holly blooms from November to December, while Japanese holly and European holly bloom from April to May.

Regarding the fruit, there is a difference: Japanese holly ripens to a purplish-black color from May to July, while Japanese holly and European holly ripen to red in November to December.

If you see bright red, ripe berries in winter, it's definitely not a holly tree.

There are also differences in the leaves. Holly and holly osmanthus have petioles that are 4 to 15 mm long, while Japanese holly and European holly have petioles that are only 2 to 5 mm long.

The rectangular shape of the leaves of Ilex crenata, with thorns at all four corners, is unique to both Ilex crenata and Ilex integra, and this is an important distinguishing feature.

What is the difference between holly and mahonia?

Berberis japonica, also known as holly maize, is another species that is often confused with holly.

However, Mahonia japonica belongs to the Berberidaceae family, which is a completely different group from holly, which belongs to the Oleaceae family.

[Seed Plant Encyclopedia #123] What are the species of the Berberidaceae family? Photo list

Berberidaceae are perennial herbs or shrubs. Their leaves are alternate and can be simple or compound. The sepals are arranged in groups of three in 3-4 whorls, or two in 4 whorls; the outer 1-2 whorls are smaller and fall off quickly during flowering, while the inner 2 whorls are larger and petal-like. The petals are 2 or...

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Mahonia japonica has odd-pinnately compound leaves, meaning each leaf is divided into 5 to 9 pairs of "leaflets," which is different from the simple-leaved holly.

The flowers of Mahonia are yellow, but those of Holly are white.

If you observe carefully, you should be able to easily distinguish them.

It should be noted that the genus Mahonia also includes other species such as Narrow-leaved Mahonia and Flat-leaved Mahonia, so distinguishing between them is a separate matter.

What are the differences between Mahonia japonica, Narrow-leaved Mahonia japonica, and Flat-leaved Mahonia japonica? We'll explain how to distinguish between similar species!

Mahonia japonica, Narrow-leaved Mahonia japonica, and Flat-leaved Mahonia japonica all belong to the Berberidaceae family, genus Berberis. They have odd-pinnately compound leaves with coarse, needle-like serrations and are frequently cultivated as ornamental plants due to their ease of growth. However, few people may be able to properly distinguish between the three species...

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Why do holly plants have leaves with thorns and leaves without?

It is known that holly has both thorny leaves (serrated leaves) and leaves without thorns (entire leaves).

Young holly trees have many serrated leaves, while as they age, they tend to have more entire leaves.

Why does the holly tree have two types of leaves, and why do entire leaves become more common as it ages?

Although there are no actual experiments to support this, it is assumed that young trees are short and at high risk of being eaten by herbivorous mammals such as Japanese deer, but as they get older and grow taller, the risk of being eaten decreases (Sonike, 2016).

In such cases, it is important for young plants to develop serrated leaves to prevent them from being eaten. However, it is likely that producing sharp, hard thorns is costly and energy-consuming, so as the plant ages, it probably develops more entire leaves to reduce waste.

What are the seed dispersal methods?

The exact method of holly seed dispersal is not fully understood, but it is known to be bird-dispersed, and at least bulbuls are known to eat them (Ueda, 1999).

You can often see young holly trees scattered throughout the forest, and it's clear that these have sprouted from bird droppings.

References

Hayashi, Masayuki. 2019. Tree Leaves: Expanded and Revised Edition - Identifying 1300 Species Through Real-Life Scans. Yama-kei Publishers, Tokyo. 824pp. ISBN: 9784635070447

Kanagawa Prefecture Flora Survey Association. 2018. Kanagawa Prefecture Flora 2018 (Electronic Edition). Kanagawa Prefecture Flora Survey Association, Odawara. 1803pp. ISBN: 9784991053726

Sonoike, Kimiyoshi. 2016. Plant shapes have meaning. Bere Publishing, Tokyo. 293pp. ISBN: 9784860644703

Ueda, Keisuke. 1999. Seed Dispersal: The Evolution of Mutual Aid, Vol. 1: Seeds Carried by Birds. Tsukiji Shokan, Tokyo. ISBN: 9784806711926

The Berberidaceae family consists of perennial herbs or shrubs. The leaves are alternate and can be simple or compound. The sepals are arranged in whorls of 3 to 4, or 2 to 4, with the outer 1-2 whorls being smaller and falling off early during flowering, while the inner 2 whorls are larger and petal-like. The petals are arranged in whorls of 2 or 3. Nectaries are located at the base of the petals. The ovary is superior and consists of one carpel. The fruit is a berry or follicle. Approximately 650 species in 16 genera are known, mainly in the temperate regions of the Northern Hemisphere, with the genus Berberis extending as far south as the southern tip of South America. In Japan, 14 species in 7 genera are distributed.

This article provides a comprehensive, illustrated guide to plants belonging to the Berberidaceae family.

The basic information is based on the Kanagawa Prefecture Flora Survey Association (2018). Photos are replaced as better ones become available. While the identification is done by the author, please note that misidentifications may be corrected without notice.

No.1166.a Dysosma versipellis

Deciduous perennial herb (Flora of China). Height 40–150 cm. The above-ground stem is erect, pale green, unbranched, and glossy. Leaves are alternate, with petioles 12–25 cm long for lower leaves and 1–3 cm long for upper leaves. The leaf blade is semi-circular, 30 cm in diameter, thin and papery, glossy on the outside, with clearly raised veins, glossy on the outside, 4–9 lobed, with lobes broadly triangular, ovate or oblong-elliptic, 2.5–4 cm long, base 5–7 cm, slightly serrated margins, and abrupt, undivided apex. Flowering period is March to June. Inflorescence is 5–8 lobed, with petals extending vertically. Pedicels are drooping, slender, and covered with soft hairs. Flowers are red and borne near the base of the leaf blade. The sepals are oblong, 0.6–1.8 cm long and 3–8 mm long, with a cottony outer surface and a glossy inner surface, and a sharply pointed tip. The petals are spatulate-elliptic, about 2.5 × 0.8 cm long, and glossy. The stamens are about 1.8 cm long, with filaments shorter than the anthers, and the anther junction is somewhat long, glossy, and sharply pointed. The ovary is elliptical and glossy, with short, shield-shaped stamens. The fruiting period is from May to September. The fruit is elliptical or ovate, about 4 × 3.5 cm long. There are many seeds. Native to China, it is cultivated as an ornamental plant in Japan and other countries. It grows in forests, woodlands, damp places in the shade of streams, and bamboo groves.

No.1169 Berberis thunbergii

Also known as Kotori-noborazu, it is a deciduous shrub. The trunk has prominent longitudinal grooves and ridges, and the leaves are modified thorns. The inner bark and wood are yellow. The leaves are clustered, obovate or elliptical with entire margins, and the underside is whitish. It flowers from April to May. The flowers are yellow, and 2 to 4 flowers hang down from the ends of short branches. The fruit is a berry that ripens to red. It is native to Japan and distributed in Honshu (west of the Kanto region), Shikoku, and Kyushu. It is cultivated as an ornamental plant in Japan and overseas, and has become naturalized in North America and Europe (CABI, 2019). It is common in mixed forests on hillsides and in windy areas in mountainous regions. The red fruit is an adaptation for bird dispersal, and it is known to be eaten by at least brown-eared bulbuls, thrushes, and azure-winged magpies (Kanouchi, 2021).

No. 1169.1 Berberis thunbergii 'Rose Glow'‘

This is a cultivated variety of barberry whose young leaves have irregular pink variegation, and as it matures, its leaves become almost entirely pink and black (to reddish-purple).

No. 1173 Mahonia japonica

This is an evergreen shrub. The pinnately compound leaves are 30-40 cm long, with sessile leaflets 4-9 cm long and 2.5-5 cm wide, bearing large, coarse, sharply pointed serrations. The leaves are leathery and glossy on the upper surface. The flowers are yellow, somewhat sparsely arranged in racemes, and mostly drooping. The berries are oval or nearly spherical and ripen to a dark purple color. Native to the Himalayas, China, and Taiwan, it is believed to have been introduced to Japan in the early Edo period. This species is the most common among those planted in parks and gardens in Japan, and escaped plants can sometimes be found in woodlands in plains, although many of these are young plants that have not yet bloomed. There is a horticultural variety that is a hybrid with B. lomariifolia, which is native to China, and has somewhat erect inflorescences that bloom earlier than Mahonia japonica (January-February). As the number of cultivated varieties increases, there is a possibility of interbreeding. When a honeybee touches a stamen while trying to drink nectar, a reflex movement occurs in the stamen, resulting in pollination (Tanaka and Hirano, 2000).

No. 1174 Narrow-leaved holly (Berberis fortunei)

This evergreen shrub has pinnately compound leaves 15-30 cm long, with sessile leaflets 7-14 cm long and 1-2 cm wide, sparsely serrated with low teeth, leathery in texture, and slightly glossy on the upper surface. The racemes are mostly ascending, and the yellow flowers are somewhat densely packed. The berries are nearly spherical and ripen to a dark purple color. Native to China, it was introduced to Japan in the early Meiji era. It is commonly planted in parks and private gardens.

No.1174.a Narihirahiiragi Mahonia (Berberis eurybracteata subsp. eurybracteata)

Evergreen shrub (Hayashi, 2014). Odd-pinnately compound leaves 20-40 cm long. Leaflets are in 5-10 pairs, 5-15 cm long. Similar to Mahonia japonica, but differs in that the leaflets are narrower and usually in more than 5 pairs. The width of the leaflets varies considerably, but in subsp. eurybracteata they are 2 cm or wider. Flowers bloom from late summer to early winter. In subsp. eurybracteata, the pedicels are 3-5 mm long. Tree height 1-2 m. Native to China, it is cultivated in Japan for ornamental purposes and can be seen as a garden tree and park tree. It grows wild in evergreen broadleaf forests, bamboo groves, forest edges, mixed forests, slopes overgrown with weeds, and open rocky areas (Flora of China). In subsp. ganpinensis, the leaflets are less than 1.5 cm wide and the pedicels are 1.5-2 mm long.

No.1175 Epimedium grandiflorum var. thunbergianum f. violaceum

This is a deciduous perennial herb. The leaves are twice-ternate compound leaves, and most wither in winter. The leaflets have an irregularly heart-shaped base, needle-like serrations along the margins, and short, spreading hairs on the underside. The flowers are reddish-purple and bloom facing downwards, with long spurs on the petals. It is distributed in Hokkaido (Oshima Peninsula) and Honshu (mostly on the Pacific side). It grows in forest edges on hillsides and in bright mixed forests. The basic variety, var. grandiflorum, is known as Yachimataikarisou and is distributed in the Kinki region and Shikoku.

What are the differences between Epimedium grandiflorum and Epimedium sempervirens? What are the different species in the Epimedium genus? Why do the flower shapes and colors differ depending on the species? What kinds of insects visit the flowers?

Both Epimedium grandiflorum and Epimedium sempervirens are wild species famous for their anchor-shaped flowers, and are also known as cultivated varieties due to their unique flower shapes. Because the differences are so subtle when focusing solely on flower shape, distinguishing them can be difficult. They rarely coexist in nature…

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No. 1177 Epimedium sempervirens

This evergreen perennial herb (a mountain flower) grows to a height of 30-60 cm. The leaves are twice-ternate compound leaves. The leaflets are stiff, distorted ovate with a tail-like tip and a deeply heart-shaped base, 5-10 cm long, with bristles along the edges. It flowers from April to May. The flowers are 3-4 cm in diameter, white to reddish-purple. The petals are four in number and have a spur. The calyx is petal-like and consists of eight parts. The four inner parts are larger, while the four outer parts are deciduous. It grows in forests in mountainous areas of Honshu (the Japan Sea side from the Tohoku region to the San'in region) in areas with heavy snowfall.

No. 1181 Epimedium x setosum

A perennial herb (a mountain flower). It grows to a height of 25-40 cm. The leaves are 1-2 times compound, with ovate-elliptic leaflets 6-10 cm long and with bristles along the edges. The flowers are white and lack spurs. It is distributed in Honshu (Chubu region) and grows in mountain forests.

No. 1183 Epimedium sagittatum var. sagittatum

Herbaceous plant (Flora of China). 30-50 cm tall. The rhizome is short, sturdy, node-like, and has numerous fibrous roots. The leaves have a base and petiole, are trifoliate compound leaves, ovate to ovate-lanceolate, 5-19 x 3-8 cm, leathery, sparsely striped on the underside, deeply or shallowly notched at the base, pointed or acuminate at the apex, the terminal leaflet has evenly rounded or oblong lobes, the lateral leaflets are oblique, the outer leaves are large and triangular and pointed, the inner leaves are small and rounded, and the margins have dense, spindle-shaped lower spines. Flowering occurs from April to May. The flower stalk has two opposite trifoliate compound leaves. The pedicels are 10-20 (up to 30) x 2-4 cm, with 20-60 whorls, sometimes 3 whorls on the lower pedicels, usually glossy, sometimes with sparse glandular hairs. The pedicels are about 1 cm long and glossy. The flowers are white, about 8 mm or less in diameter. The outer sepals are four in number, with purple spots, and have blunt tips. The outer pair are narrowly ovate, about 3.5 × 1.5 mm, while the inner pair are oblong, about 4.5 × 2 mm. The inner sepals are white, ovate, about 4 × 2 mm, and have acute tips. The petals are brownish-yellow, sac-like, 1.5–4 mm, and blunt. The stamens are long, 3–5 mm, with anthers 2–3 mm. The pistil is about 3 mm, and the stamens are longer than the ovary. Fruiting occurs from May to July. The capsule is about 1 cm, and the pedicel is about 6 mm. In var. glabratum, the underside of the leaflets is glabrous, the terminal leaflet is oblong, and the flowers are yellow.

No. 1185 Nandina domestica

This is an evergreen shrub that grows to a height of about 3 meters. The bark is brown, with vertical grooves and the bases of withered leaves remaining at the top. The leaves are alternate, 3-pinnately compound. The leaflets are lanceolate, 3-7 cm long and 1-2.5 cm wide, with sharply pointed tips and entire margins. They are leathery and glossy on the surface. It flowers from May to June. Large, conical inflorescences emerge from the tips of the branches, bearing numerous white flowers 6-7 mm in diameter. The perianth segments are arranged in whorls of three, becoming larger towards the inside, with the innermost six being petal-like. There are six stamens with short filaments. The fruit is a berry, spherical, 6-7 mm in diameter, ripening red in October and November. The seeds are nearly spherical, 5-6 mm in diameter, usually two per fruit. While it can grow wild in the mountains and fields of warm regions from Ibaraki Prefecture westward to Kyushu, it is mostly cultivated as a garden tree. It is distributed in Japan, China, and India, and has been introduced to southeastern North America, the West Indies, and South America (Peru) (Flora of China). Most of the plants growing in the mountains and fields are rare specimens, and some believe that it was originally introduced from China, and that its natural habitat in Japan is questionable. Because the Japanese name for Nandina (Nanten) sounds similar to "turning misfortune into fortune," it is considered an auspicious tree and is especially used for warding off evil, purification, and fire prevention, placed near the northeast and southwest corners of the country, near toilets, and as a potted plant for New Year's. There are records in literature of honeybees visiting the flowers (Negoro, 2009), and several photographs of Japanese honeybees visiting the flowers can be found on the internet. Morphologically, although it is a berry, the relatively dry red fruit is an adaptation for bird dispersal, and it is known to be eaten by starlings at least (Ueda, 1999).

No.1185.1 Otafuku Nandina domestica 'Otafukunanten'‘

This dwarf variety of Nandina has a height of approximately 30 cm and leaves that are slightly wider and rounder than those of the common Nandina. Its beautiful autumn foliage makes it popular for planting along streets and in flowerbeds.

References

CABI. 2019. Berberis thunbergii (Japanese barberry). CABI Compendium. https://doi.org/10.1079/cabicompendium.8808

Hayashi, Masayuki. 2014. 1100 Tree Leaves Identified Through Real-Life Scans. Yama-kei Publishers, Tokyo. 759pp. ISBN: 9784635070324

Kanagawa Prefecture Flora Survey Association. 2018. Kanagawa Prefecture Flora 2018 (Electronic Edition). Kanagawa Prefecture Flora Survey Association, Odawara. 1803pp. ISBN: 9784991053726

Kanouchi, Takuya. 2021. Handbook of Wild Birds and Tree Nuts (Revised and Expanded Edition). Bun-ichi Sogo Shuppan, Tokyo. 104pp. ISBN: 9784829981672

Negoro, Takashi. 2009. Survey of flower-visiting insects at Kojō Park in Takaoka City, and comparison of survey results at 11 locations in Toyama Prefecture. Research Report of the Toyama City Science Museum 32: 39-60. https://www.tsm.toyama.toyama.jp/_ex/exfiles/bull/32/2009_04.pdf

Tanaka, Hajime & Hirano, Takahisa. 2000. The Face of Flowers: Wisdom for Bearing Fruit. Yama-kei Publishers, Tokyo. 191pp. ISBN: 9784635063043

Ueda, Keisuke. 1999. Unexpected Birds' Unexpected Preferences: Who Eats the Inconspicuous "Dry Fruit"?. In: Ueda, Keisuke (Ed.), Seed Dispersal: The Evolution of Mutual Aid Vol. 1: Seeds Carried by Birds (pp. 64-75). Tsukiji Shokan. ISBN: 9784806711926

Both Epimedium grandiflorum and Epimedium sempervirens are wild species famous for their anchor-shaped flowers, and are also known as cultivated varieties due to their unique flower shapes. Focusing solely on flower shape, the differences are subtle, making them difficult to distinguish. While they are unlikely to coexist in nature, confusion can occur in botanical gardens and horticulture. However, distinguishing between Epimedium grandiflorum and Epimedium sempervirens is not difficult with practice. They can be clearly differentiated by examining the glossiness and base of the leaflets. Other Japanese Epimedium species can be broadly classified into three types based on the length of the spur (the anchor-like part of the flower): long spur, short spur, and no spur at all. These differences in spur length are thought to serve to separate pollinating insects from closely related species, a theory that has been studied and proven in the field. However, some bees have been observed visiting all types, a curious phenomenon that could overturn this hypothesis. Epimedium species are also known for their diversity in flower color, but current research suggests this has little impact on the species' coloration. The fruit is a follicle, and the seeds inside are dispersed by ants. This article will explain the classification, pollination ecology, and seed dispersal of the Epimedium genus.

Two species with anchor-like flowers, known both as wild and cultivated varieties.

Epimedium grandiflorum var. thunbergianum, also known as "Ikarisou" (anchor grass), is a perennial herb distributed in Hokkaido (Oshima Peninsula) and Honshu (mostly on the Pacific side), growing in plains and low mountainous areas (Oshima, 2002; Shufu to Seikatsu Sha, 2007).

Epimedium sempervirens, also known as evergreen sprout, is a perennial herb distributed in the temperate to warm temperate zones along the Sea of Japan coast of Honshu (from the Hokuriku region to the San'in region), growing in the undergrowth of forests in mountainous areas with heavy snowfall.

Both belong to the Epimedium genus of the Berberidaceae family and are famous for their anchor-shaped flowers. Because the flower shapes are so similar, they are difficult to distinguish. While they are unlikely to coexist in nature, they may be confused in botanical gardens and horticulture.

[Seed Plant Encyclopedia #123] What are the species of the Berberidaceae family? Photo list

Berberidaceae are perennial herbs or shrubs. Their leaves are alternate and can be simple or compound. The sepals are arranged in groups of three in 3-4 whorls, or two in 4 whorls; the outer 1-2 whorls are smaller and fall off quickly during flowering, while the inner 2 whorls are larger and petal-like. The petals are 2 or...

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What are the differences between Epimedium grandiflorum and Epimedium sempervirens?

However, the difference between Epimedium grandiflorum and Epimedium sempervirens isn't that difficult once you get used to it.

First, let's look at the leaves. The leaves are bipinnately compound, meaning that, broadly speaking, what was originally a single leaf has divided into what are called "leaflets."

In Epimedium grandiflorum, the leaves are not evergreen and the base of the leaflets is shallowly heart-shaped, whereas in Epimedium grandiflorum, the leaves are evergreen and the base of the leaflets is deeply heart-shaped.

The term "evergreen" might be a bit confusing, but it refers to the ability to survive the winter with its leaves intact. Evergreen plants often evolve to have leaves that are harder and glossier in order to survive the winter.

Even comparing Epimedium grandiflorum and Epimedium sempervirens, Epimedium sempervirens is clearly glossier and has a firmer texture than Epimedium grandiflorum. Please compare them in the photos. This is thought to be because Epimedium sempervirens has adapted to the environment of the snowy regions on the Sea of Japan side.

Also, "heart-shaped base" can be rephrased as referring to a heart shape. A deep heart shape means that the Epimedium grandiflorum has a shape closer to a heart than the Epimedium grandiflorum.

Regarding the flower color, it is generally stated that Epimedium grandiflorum is pale reddish-purple, while Epimedium grandiflorum is white.

However, the only variety of Epimedium with pale reddish-purple flowers is called f. violaceum ; there is also a variety called white Epimedium f. humile with white flowers.

Furthermore, the white-flowered Epimedium grandiflorum is only found in the Noto Peninsula and is known as var. sempervirens. There is also a variety called Epimedium grandiflorum var. hypoglaucum, which has reddish-purple flowers and is distributed from southern Fukui Prefecture westward.

Considering this, it would be best not to rely on color for identification.

What is a simple way to distinguish between different species of Epimedium in Japan?

These two species can be distinguished in this way, but there are many other species of the Epimedium genus that are distributed in isolation in Japan. I will omit the precise classification method, but I will briefly describe their characteristics.

Epimedium species generally bloom in spring, from April to May. As the name suggests, the petals have a spur-like projection that hangs down and extends at the end; this is actually a developed part of the four petals, botanically known as a "spur." The calyx consists of eight petal-like parts, with the four inner ones being larger and the four outer ones being deciduous.

Japanese Epimedium species can be divided into three types: those with a long spur, those with a short spur, and those without a spur at all.

In addition to the previously mentioned Epimedium grandiflorum and Epimedium sempervirens, the types with long spurs include Epimedium grandiflorum var. grandiflorum (white flowers, distributed in the Kinki region of Honshu and limestone areas of Shikoku), Epimedium grandiflorum var. higoense (white flowers, distributed in Kumamoto Prefecture, Kyushu), and Epimedium koreanum (pale yellow flowers, distributed in the Oshima Peninsula of Hokkaido, mainly the Sea of Japan side of Honshu, the northern part of the Korean Peninsula, and the Ussuri region of Japan).

Types with short spurs include * Epimedium trifoliatobinatum* subsp. *trifoliatobinatum * (distributed in the serpentine areas of Shikoku) and * Epimedium trifoliatobinatum * subsp. *maritimum* (distributed near the coast and islands of eastern Kyushu, evergreen).

Types that completely lack spurs include * Epimedium diphyllum subsp. diphyllum* (white flowers, distributed in the Chugoku region of Honshu, Shikoku, and Kyushu) and *Epimedium diphyllum subsp. kitamuranum* (distributed in the Yoshino River basin of Shikoku).

There is also Epimedium x setosum, which exhibits great morphological variation in flower color, presence or absence of spurs, etc. (distributed in limestone areas of the Chugoku region of Honshu, a hybrid of Epimedium grandiflorum and Epimedium sempervirens).

Why do Epimedium flowers have different shapes depending on the species?

As you can see, there are three types of flowers in the Epimedium genus, depending on the length of their spurs. Why do they differ in shape in this way?

The most likely explanation is that each species uses different pollinating insects for pollination.

There is nectar at the end of the spur, but by creating a long spur, it is possible to limit the insects that come to drink the nectar to species with long tongues that match the length of the spur. Conversely, by eliminating the spur, the reward of nectar is removed, and insects that prefer pollen, such as bees, can be attracted.

This will prevent competition for pollinating insects even when different species of the same Epimedium genus coexist, and it will also prevent hybridization, thus avoiding the risk of producing sterile seeds or seeds that cannot reproduce.

There are three types of Epimedium flowers, and each attracts different insects!?

To investigate whether this is true, Japanese researchers have patiently conducted field surveys of insects that visit three types of Epimedium flowers throughout Japan, though not all of them (Suzuki, 1983; Suzuki, 1984; Suzuki, 1990).

As a result, we discovered that the three types exhibited different tendencies.

First, the types with long spurs were mainly visited by the bumblebee *Bombus diversus diversus*, which efficiently pollinated them. *Bombus diversus* is well known for its long tongue. *Bombus nipponensis* was also present, but in very small numbers.

To drink the nectar at the end of the long spur, the bee must extend its tongue through the opening in the center where the stamens are located. Moreover, since the opening is on the underside, it has to hang upside down. Only certain bumblebee species with long tongues, such as the tiger bumblebee, are able to do this. Furthermore, from an ecological perspective, it is known that bumblebees actively collect nectar in the spring as a source of nutrition for the queen bee to build her nest.

Furthermore, the types with short spurs were primarily visited and efficiently pollinated by Eucera nipponensis. Some bumblebee species with long tongues, such as Bombus scoparius, did not visit them at all. Eucera nipponensis has a relatively long tongue, but it is shorter than that of Bombus scoparius.

To suck nectar from the tip of a short spur, a tongue as long as that of a bumblebee (like the Japanese bumblebee) is actually inefficient; a tongue length similar to that of a Japanese long-horned bee (like the Japanese long-horned bee) seems to be just right.

Finally, in the type of flower that lacked a spur at all, pollinating bees took priority in visiting and efficiently pollinating the flowers. While some Japanese long-horned bees (Nippon-higenaga-hanabachi) were also present, they were very few in number.

The complete absence of a spur means that the only reward for insects is pollen, making the flower attractive only to bees that collect pollen.

As the results clearly show across the three types, it might appear at first glance that they are able to coexist and avoid the risk of hybridization.

Was the supposedly clever isolation of different Epimedium species incomplete?

However, the complexity and fascination of nature lie in the fact that it doesn't always allow us to understand it so easily.

Surprisingly, the pollen-collecting bees that appeared at the end weren't just those with no spurs at all; those with long spurs and those with short spurs also visited the area.

This defeats the purpose of trying to avoid habitat segregation and hybridization. Why is this happening?

Currently, this mystery remains unsolved. It is known as one of the mysteries known as the "double structure."

However, one possibility is that the foraging range of the bees that collect pollen is not very wide. If the bees that collect pollen do not travel far, the probability of them carrying pollen to other Epimedium species is likely low. This point has not yet been verified, but the researchers who conducted this study believe this is a likely possibility.

Do differences in flower color in the Epimedium genus affect pollinating insects?

One notable characteristic of the Epimedium genus is its great variation in color. Generally, they range from pale reddish-purple to white, with yellow being the most common.

Do these color variations affect the types of insects that visit the flowers?

Similarly, according to the research results mentioned earlier, it is believed that color is not affected.

This is suggested by observations of estimated hybrid populations of Epimedium grandiflorum and Epimedium sempervirens.

In this group, there are no pure reddish-purple flowers; instead, various intermediate color variations ranging from reddish-purple to pale yellow (to green) are observed. However, it has been observed that the same bumblebee queen visits flowers of all different colors without distinction.

Other observations have also reported that bumblebees visit flowers regardless of their color, reinforcing the idea that bumblebees do not perceive red, and that red flowers contain the same pigments as yellow flowers, does not influence their behavior.

However, if the difference in color did not affect pollinating insects, then polymorphism in the color of bumblebee-pollinated flowers should be observed more frequently in nature. Nevertheless, considering species such as toad lilies and balsams, this does not seem to be the case (although the color does indeed change between species).

Considering this, I personally would like to think that the diversity of Epimedium flower colors is due to some kind of adaptation resulting from competition with other insect faunas in the region or with the flower colors of other plants, but the detailed reasons remain unclear. I look forward to future research.

The fruit is a follicle, and the seeds are dispersed by ants.

The fruit is a follicle resembling a bean pod, containing 5 to 8 seeds. The seeds have elaiosomes that are attractive to ants, and are dispersed by ants (Suzuki, 1990).

References

Oshima, Toshiaki. 2002. Wildflowers and Alpine Plants Selected by Flower Color. Seibido Publishing, Tokyo. 463pp. ISBN: 9784415019062

Suzuki, Kazuo. 1983. Pollination patterns of the genus Epimedium. *Journal of Species Biology* 7: 72-81. ISSN: 0913-5561, https://dl.ndl.go.jp/info:ndljp/pid/10467757

Suzuki, K. 1984. Pollination system and its significance on isolation and hybridization in Japanese Epimedium (Berberidaceae). The Botanical Magazine 97(3): 381-396. ISSN: 0006-808X, https://doi.org/10.1007/BF02488670

Suzuki, Kazuo. 1990. Japanese Epimedium: Origin and Speciation. Yasaka Shobo, Tokyo. 187pp. ISBN: 9784896948035

Shufu to Seikatsu Sha. 2007. A Guide to Wildflowers Found in the Fields and Mountains. Shufu to Seikatsu Sha, Tokyo. 143pp. ISBN: 9784391134254

Source

This article is a significantly expanded version of a piece originally published in the following book.