Monday, February 22, 2021

[Botany • 2021] Ephedra chengiae (Ephedraceae) • A New Species from Xizang of China

Ephedra chengiae  Y. Yang & D.K. Ferguson
Ephedra chengiae var. spinosa Y. Yang & D.K. Ferguson

in Yang & Ferguson, 2021. 
A new species of Ephedraceae, i.e. Ephedra chengiae sp. nov., is described and illustrated here. This new species is similar to E. rituensis Y.Yang & al. and E. intermedia Schrenk & C.A.Mey. in the erect habit with prominent woody stems, elongated twigs with many nodes, and the long micropylar tube. However, it differs from E. rituensis by the synangia being prominently stipitate (vs. sessile), the female cone having fewer bract pairs (3–4 vs. 4–5), its glossy seeds, and from E. intermedia by the prominently stipitate synangia (vs. sessile or nearly so), the female cone having fewer bract pairs (3–4 vs. 2–5), the glossy seeds (vs. seeds not glossy), and the micropylar tube being more or less straight (vs. twisted). Ephedra chengiae var. spinosa var. nov. differs from var. chengiae in its cushion-like habit and the spinose twigs.

Keyword: China, Ephedra rituensis, Ephedra intermedia, Ephedraceae, morphology, new species, taxonomy, Xizang

Fig. 2. Ecological photos of Ephedra chengiae sp. nov. displaying habit and habitat.
A, female plant; B, male plant.

Fig. 1. Illustrations of Ephedra chengiae sp. nov. (A-F)
and var. spinosa var. nov. (G-H);
A, a plant displaying the erect habit; B, a female cone showing the fleshy bracts and the enclosed chlamydosperms; C & D, chlamydosperms displaying the ovoid-ellipsoid shape and the long and straight micropylar tube; E, a male cone revealing the exposed synangia with apical openings; F, a pair of bracteoles subtending a median synangiophore with terminal stipitate synangia;
G, a plant of var. spinosa exhibiting the cushion-like habit and the spinose twigs; H, a twig displaying the spinose shape.
Abbreviations: br, bracts; bt, bracteoles; mt, micropylar tube; si, synangium.

Ephedra chengiae Y. Yang & D.K. Ferguson, sp. nov.

Diagnosis: This species is similar to Ephedra rituensis Y.Yang et al. and E. intermedia Schrenk & C.A.Mey. in the long micropylar tube, but differs from the latter two species by the stipitate synangia (vs. sessile synangia), female cones having fewer pairs of bracts (3– 4 vs. up to 5), and the glossy seeds (vs. seeds not glossy).

Etymology: The specific epithet is derived from Ching-Yung Cheng for her contributions to taxonomic knowledge of Chinese gnetophytes. Prof. Cheng was the author of the Chlamydospermopsida in Flora Reipublicae Popularis Sinicae (Cheng, 1978). 

Habitat: The species lives in rock crevices or on slopes of sand dunes. 

Distribution: The species is distributed in western Xizang of China (Fig. 3, black solid square).

Ephedra chengiae var. spinosa Y. Yang & D.K. Ferguson, var. nov. 

Diagnosis: The new variety differs from E. chengiae var. chengiae in the dwarf and cushion-like habit, straight and spinose twigs with 1–2 internodes (vs. erect shrub, twigs not spinose with more than 3 nodes). 

Etymology: The specific epithet is derived from the spinose twigs

Distribution: This new variety is only known from Lhozhag County of Xizang in China (Fig. 3, triangle).  

Yong Yang and David K. Ferguson. 2021. Ephedra chengiae (Ephedraceae), A New Species from Xizang of China. Taiwania. 66(1); 57 - 60. DOI: 10.6165/tai.2021.66.57