Skip to main content

Takenoshin Nakai swallow-wort (Vincetoxicum nakaianum) replaces V. magnificum and C. magnificum

Takenoshin Nakai swallow-wort (Vincetoxicum nakaianum) replaces V. magnificum and C. magnificum

NEWS - Researchers reported an erect herbaceous species distributed in the eastern part of Honshu Island, Vincetoxicum magnificum (Nakai) Kitag. based on Cynanchum magnificum Nakai, nomen nudum. Therefore, they named this species Takenoshin Nakai swallow-wort (Vincetoxicum nakaianum K.Mochizuki & Ohi-Toma).

Vincetoxicum Wolf (Asclepiadeae) is the third largest genus in the Asclepiadoideae consisting of about 260 species geographically extending from tropical Africa, Asia and Oceania to temperate regions of Eurasia.

A total of 23 species are known from Japan, including 16 endemic species. Molecular phylogeny divides Japanese Vincetoxicum into four groups: the “Far Eastern” clade consisting of 11 endemic species and 4 more widespread species, 1 sister species to the “Far Eastern” clade, the “subtropical” clade consisting of 2 species and the “Vincetoxicum s. str.” clade consisting of 5 species.

V. magnificum (Nakai) Kitag. (Japanese: tachi-gashiwa) is closely related to V. macrophyllum Siebold. & Zucc. (Japanese: tsukushi-gashiwa) and V. macrophyllum var. nikoense Maxim. (≡Cynanchum nikoense (Maxim.) Makino; Japanese: tsuru-gashiwa) which belong to the basal lineage of the clade “Vincetoxicum s.str.”.

These three taxa have been recognized in several publications so far, including the current Japanese flora. Recently, the author introduced V. magnificum in Curtis’s Botanical Magazine, but the name is not legally published according to the International Code of Nomenclature.

The species was first published by Nakai (1937) as C. magnificum Nakai, in connection with a taxonomic study of the related species V. macrophyllum (as Cynanchum grandifolium Hemsl.) and V. macrophyllum var. nikoense (as Cynanchum nikoense (Maxim.) Makino).

In the publication, the name C. magnificum Nakai was proposed for the “tachi-gashiwa” population distributed in the Kanto region of Honshu, Japan, but no Latin description, diagnosis or even indirect reference to a previous description was given. Therefore, the name C. magnificum Nakai is a nomen nudum (ICN Art. 38.1 and 39.1).

Later, based on this nomen nudum, Kitagawa (1959) published V. magnificum (Nakai) Kitag.; therefore, this combination was not validly published. Furthermore, the name cannot be considered a novum species, “Vincetoxicum magnificum Kitag.”, because it is not accompanied by a description, diagnosis or reference to a previously published Latin description or diagnosis.

In the present study, the Japanese species “tachi-gashiwa” was validly described as V. nakaianum K.Mochizuki & Ohi-Toma with a detailed description. In this case, the proposed name is not “nomen novum” but “species nova” because C. magnificum and V. magnificum have never been legally published.

V. nakaianum is morphologically similar to V. macrophyllum but is distinguished by erect stems ending in inflorescences and larger flowers, green to brownish, 10-15 mm in diameter. (vs. dark purple flowers and 4-5 mm in diameter) with glabrous crowns (vs. villi).

Flowering March-May and fruiting June-February. Elevation 100-850 m. This species grows in Japanese cedar plantation forests and deciduous forests dominated by Fagus japonica Maxim., Abies firma Siebold & Zucc., Quercus L., Acer L., and Carpinus L. The species epithet is given in honor of Prof. Takenoshin Nakai (1882-1952).

Original research

Mochizuki K, Nemoto S, Murata J, Ohi-Toma T (2024). Vincetoxicum nakaianum (Asclepiadoideae, Apocynaceae), a new species from Japan for Cynanchum magnificum Nakai, nomen nudum. PhytoKeys 247: 191-201, DOI:10.3897/phytokeys.247.125070

Dlium theDlium
Labels:

Popular Posts

Indian shot (Canna indica)

Puspa midra or Indian shot ( Canna indica ) is is plant species in Cannaceae, annual, shrub 0.5-2.5 meters high, depending on variety, erect stems, unbranched and leaf midrib arranged overlapping to form pseudostems and hermaphrodite flowers. C. indica forms a branched rhizome, 60 cm long which is divided into rounded segments and is covered in two stripes by pale green or purple scaly leaves. The rhizome has tubers that contain very large starch grains. The surface has transverse furrows, the underside appears white roots and numerous shoots. The leaves sit alternate and spiral or arranged in two rows, very large and divided into a leaf midrib, short stalk and blade. The strands are 30-60 cm long, 10-20 cm wide and have linear veins, green or purple-green, the base blunt or narrowly pointed and the apex immediately tapering or sharp. Hermaphrodite flowers, pedicels 0.2-1 cm long and red or yellow-orange, except in some cultivars 4.5-7.5 cm long. The sepals are triangular in shape a...
Read more

Guinea grass (Panicum maximum)

Guinea grass or buffalo grass or green panic ( Panicum maximum ) is a plant species in Poaceae, annual grasses, growing upright to form clumps, strong, cultivated in all tropical and subtropical regions for very high value as fodder. P. maximum reproduces in very large pols, fibrous roots penetrate into the soil, upright stems, green, 1-1.5 m tall and have smooth cavities for diameters up to 2.5 mm. Propagation is done vegetatively and generatively. Ribbon-shaped leaves with a pointed tip, very many, built in lines, green, 40-105 cm long, 10-30 mm wide, erect, branched, a white linear bone, often covered with a layer of white wax, rough surface by hair short, dense and spread. The flower grows at the end of a long and upright stalk, open with the main axis length to more than 25 cm and the length of the bunches down to 20 cm. Grains have a size of 3x4 mm and oval. Seeds have a length of 2.25-2.50 mm and each 1 kg contains 1.2 - 1.5 million seeds. Guinea grass has two varieties. P...
Read more

Indian rosewood (Dalbergia latifolia)

Sonokeling or Java palisandre or Indian rosewood ( Dalbergia latifolia ) is a species of plant in the Fabaceae, a large tree producing hardwood, medium weight and high quality, rounded leaves, thin and broad pods, highly adaptive, grows in dry and rocky landscapes with lots of sunlight. D. latifolia has medium to large size, cylindrical stems, up to 40 m high with a ring of up to 2 m, the bark is brownish gray and slightly cracked longitudinally. The crown is dense, dome-shaped and sheds leaves. The leaves are compound and pinnate oddly with 5-7 strands that have different sizes and appear alternately on the shaft. The leaves are round or elongated in width or heart, the upper surface is green and the surface is pale green. The flowers are small, 0.5-1 cm long and clustered in panicles. The pods are green to brown when ripe and are elongated lanceolate, pointed at the base and tip. The pods have 1-4 seeds which are soft and brownish. Indian rosewood grows at elevations below 600 m,...
Read more