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

Crested blue ear (Cyanotis cristata)

Crested blue ear ( Cyanotis cristata ) is a species of plant in the Commelinaceae, a fleshy and strong herb, growing as a vine. Leaves 8 cm long, 2.5 cm wide, oblong, rounded or heart-shaped base, blunt or pointed tip, sparsely ciliated at the edge; sheath loose, up to 8 mm long, scaly. C. cristata has flowers 6-7 mm in diameter. Calyx tube 2 mm long, lobes 2-2.5 mm long, hairy. Corolla pale blue to purple, 6 mm long. Stamen filaments bearded, purple. Ovary rounded, hairy at the apex. Capsules 2-3 mm long, ovate. Seeds about 1 mm long, trigonous, 2 large holes on either side. This species grows in grasslands, degraded forest areas, wastelands, waterways and roadsides. C. cristata is found in wet rocky areas, moist soils, grasslands, ravines and riverbanks. Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiospermae Class: Liliopsida Order: Commelinales Family: Commelinaceae Subfamily: Commelinoideae Tribe: Tradescantieae Genus: Cyanotis Species: Cyanotis cristata
Read more

False ashoka (Monoon longifolium)

False ashoka ( Monoon longifolium ) is a plant species in the Annonaceae, a small tree, evergreen, up to more than 20 meters high, symmetrical pyramidal with pendulous branches, hardwood, easy to grow and very adaptive. M. longifolium has long narrow lanceolate leaves with wavy edges, 25 cm long, 6 cm wide, copper brown pigmentation but over time becomes bright green and finally dark green. Pale green flowers resemble delicate stars. The flowering period is usually 2-3 weeks. Fruits in 10-20 pieces, round, up to 2 cm wide, green but turn purple or black when ripe. Trees are used to filter air pollution. Leaves are used for decorative decoration during festivals. Trees are easily pruned into various shapes and maintained in the required size. Flexible, straight and light rods are used in making sailing ship masts. Wood for making pencils, boxes and matches. Seed oil has anti-oxidant, anti-lipooxygenase and antimicrobial activity. Kingdom: Plantae Phylum: Tracheophyta Subphylum: An...
Read more

Broad-leaved dock (Rumex obtusifolius)

Broad-leaved dock ( Rumex obtusifolius ) is a species of plant in the Polygonaceae, herbaceous perennial, growing broadly, up to 150 cm tall, large, oval-shaped leaves with a heart-shaped base and rounded tip, large taproot with many branches extending to a depth of 150 cm. R. obtusifolius has leaves up to 30 cm long, 15 cm wide and green. Stems are long, hard, alternate, green or reddish in color and unbranched until just below the inflorescence. A main vein in the middle and green or reddish in color. Flat or wavy surface. The inflorescences consist of large clusters of racemes that contain small, greenish flowers that turn red as they mature. Seeds are reddish brown and dry. Broad-leaved dock grows in fertile soils, grasslands, waste lands, roadsides, ditches, coastlines and riverbanks, forest margins, forest clearing and agricultural land. The leaves are used as a salad to make vegetable broth or cooked like spinach. Dried seeds are used as a spice. Kingdom: Plantae Phylum: Tr...
Read more