Rohdea changii Hui Zhe Feng & Z. Qiang, Lu, 2021

Feng, Hui Zhe & Lu, Zhi Qiang, 2021, Rohdea changii (Asparagaceae), A New Species from Northwestern Yunnan, China, Phytotaxa 508 (1), pp. 93-100 : 93-97

Rohdea changii Hui Zhe Feng & Z. Qiang, Lu , sp. nov. ( Figs. 1 , 3C & 3G )

Type:— CHINA. Yunnan, Diqing, Weixi , alt. 2550 m, 5 March 2021, H. Z. Feng & Z. Q. Lu 1122 (holotype, HITBC!) .

Diagnosis: The new species resembles Rohdea nepalensis , but differs by the oblanceolate leaf blades, acute leaf apices, bracts often distally lobed, entire bract margins, oblique-zygomorphic flowers, flowers tuning to nearly white at late and after anthesis, urceolate perianth, entire filament margins for widened part (filaments proximally widened and adnate to perianth tube), 6 to 9 stamens, and 5-lobed stigmas.

Description: Rhizome terete, ca. 2.0 cm in diam., multi-branches, brown, densely annulate with leaf scars, bearing fleshy thick roots to ca. 3.0 mm in diam., covered with remnant bases of sheath-leaves. Roots 3.0-4.0 mm in diam., densely pubescent when young. Stem nearly erect, cylindrical, short, to 3.0 cm in length, densely covered with leaves and scaly leaves. Leaves congested, basal, erect, petiole inconspicuous; oblanceolate, basally amplexicaul, margins entire, weakly wavy, abruptly taper, recurved, 20–35 × 2.0–4.0 cm, with prominent midrib. Inflorescences axillary in apical part of rhizomatous stem; glabrous; peduncle erect, straight, rigid, glabrous, 4.0–5.0 cm in length, 5.0–7.0 mm in diam.. Spike densely many flowered, 6.0–7.0 cm in length, 2.5–3.5 cm in diam., simple, with few sterile bracts apically. Fertile bract 1 per flower, lanceolate, 2.0–6.0 × 0.5–1.0 cm, longer than the flower, green, with white membranous, margin entire, apically dehiscent. Flowers sessile, green, and turn to nearly white laterly, oblique-zygomorphic. Perianth campanulate, 6(-9)-lobed; lobes not spreading, 2.0–2.5 × 3.0–4.0 mm, thick, triangular, fleshy, inside with verruculose, dentate margin; tube 5.0–6.0 mm in length. Stamens six to nine, as many as and opposite perianth lobes; filaments proximally widened and adnate to perianth tube, widened part entire at margin, free part 1.0–2.0 mm in length and incurved; anthers ellipsoid, 1.0–1.5 × 0.7–1.0 mm wide, pale-yellow, dorsifixed, extrorse, overtopping the stigma. Pistil one; style very short, inconspicuous; stigma 5-lobed, each lobe ovate to almost half-circular, curved abaxially downwards. Ovary superior, subglobose, ca. 3.0 mm in diam., light green. Fruit berry-like, subglobose, sessile, ca 1.5 cm in diam., orange at maturity, globose and with persistent remnant of the style at apex. Flowering in March, fruiting in November–March.

Etymology:—This new species is in honour of Prof. Chang Hungtag (1914—2016) of Sun Yat-sen University for his excellent contributions to the taxonomy of Southern China.

Distribution:—This new species is currently known only from Weixi, Diqing, Yunnan, China.

Taxonomic relationships:—The comparison with the known species of Rohdea indicates that R. changii is similar to R. nepalensis , R. siamensis and R. wattii , because they share the unique character that they have the long bracts exceeding the flowers. However, R. changii is distinctly different from these three closely related species by the oblanceolate leaf blades, acute leaf apices, bracts often distally lobed, oblique-zygomorphic flowers, flowers tuning to nearly white at late and after anthesis, 6 to 9 stamens, and 5-lobed stigmas ( Figs 1 , 2 , 3 & 4 ; Table 1 ). In addition, there are some other characters that can be distinguishable between R. changii and any one of three closely related species. For example, R. changii differs from R. nepalensis by the entire bract margins, and urceolate perianth, and entire filament margins for widened part (filaments proximally widened and adnate to perianth tube); R. changii differs from R. siamensis by the shorter leaf blades, lanceolate bracts, entire bract margins, verruculose abaxial surface of perianth lobe; R. changii differs from R. wattii by the longer but narrower leaf blades without distinct petioles, urceolate perianth, entire margins for perianth lobes, and verruculose abaxial surface of perianth lobe.

Although R. changii and R. nepalensis with the closest morphology co-occur in the same place, their habitats are very different. R. changii grows in sparse bush and dry rock slopes (vs. dense forests, mixed forests along valleys, shady rocky slopes for R. nepalensis ). Most important of all, flowering time between R. changii and R. nepalensis is also distinctly different. Our observation on phenology in the common garden (put them together in our office) suggested that the new species had flower buds and ripened fruits in 5 March 2021, and began to flower in 16 March 2021 and wither in 25 March 2021. However, we only found that R. nepalensis had immature fruits without flower buds in 5 March 2021, and flower buds began to come out in 25 March 2021 ( Fig. 3 A, B, D, E, F, H & I ). Hence, this new species ( R. changii ) is distinctly different from R. nepalensis based on multiple lines of evidence from habitat differentiation, phenology isolation and phenotypic divergence.

Figures

FIGURE 1. Rohdea changii. A. habitat; B. Rhizome; C. Inflorescence with one opening flower with seven stamens; D. Flower with nine stamens; E. Flower with eight stamens; F. Bracts; G. Inflorescence at late or after anthesis; H. Flower, side view; I. Flower, front view; J. Flower with nine stamens; K. Leaf blade.

FIGURE 2. Holotype of Rohdea nepalensis. Nepal, Narainhetty, B. H. Francis s. n. (BM-000521469).

FIGURE 3. Rohdea nepalensis (A, B, D & F) & R. changii (E).A. Inflorescences. B. Bracts. C & D. Flowers. E & F. Fruits (photographed in the overlapped regions with the similar altitude at the same day).

FIGURE 4. Rohdea wattii. A. Habitat; B. Inflorescences; C. Flower; D. Leaf blades.