Dysphania geoffreyi Sukhor., 2015

Sukhorukov, Alexander P., Zhang, Mingli & Kushunina, Maria, 2015, A new species of Dysphania (Chenopodioideae, Chenopodiaceae) from South-West Tibet and East Himalaya, Phytotaxa 203 (2), pp. 138-146 : 139

Dysphania geoffreyi Sukhor. sp. nov.

Holotype 1:— CHINA. Tibet [Xizang prov.]: Lhasa, Daxika , grassy slope, 4150 m, herb with green flowers, 5 September 1965, Yong-tian Zhang & Kai-yong Lang 2663 (PE-00510980!)* ( Fig. 1 ).

Description: —Annual, 5–50 cm tall, stem erect, often scarcely branched and then only in the upper part, branches directed upwards; leaves pinnatifid or lobate, appressed to the stem, up to 2 cm long, shortly petiolate (petioles 0.2–0.5 cm), lower leaves caducous at flowering and fruiting times. Inflorescence leafy, lateral branches appressed to the stem or obliquely directed, narrowly cylindrical but never spreading, with axis covered with short simple hairs up to 0.3 mm long mixed with glandular trichomes. Perianth segments 5, cristate on dorsal surface (especially on midrib) with numerous large simple stout hairs up to 0.3 mm, the bases of which can sometimes be concrescent resulting in 2−3- furcate tips, intermixed with yellow subsessile glands and scattered glandular hairs ( Fig. 2 ). Pericarp separates from the seed, with tiny volcano-like papillae. Seed subspherical, 0.5–0.6 mm in diameter; embryo horizontal.

Etymology: —The species is named after Dr. Geoffrey Harper (b. 1944), formerly a developmental physiologist at Royal Botanic Garden Edinburgh ( UK).

Habitat: —Grassy slopes, gravelly substrates, sands and ruderal sites; 2500–4200 m.

Phenology: —Flowering July–September; fruiting August–October.

Conservation status:—The appropriate data on abundance and/or distribution of the taxon is lacking. It can be included in the Not Evaluated (NE) category of IUCN Red List categories ( IUCN 2010) as there is inadequate information to make a direct or indirect assessment of its risk of extinction based on its distribution and/or population status.

Notes: —Specimens of D. geoffreyi used to be identified as D. botrys or D. nepalensis . The new species is notable for several characters, such as 1) at least the upper leaves as well as the inflorescence branches being appressed to the stem, 2) very short leaf petioles (up to 0.5 cm), 3) the remarkable indumentum set on the perianth segments, and 4) the smallest seeds among all Eurasian Dysphania species. Fruit morphology of D. geoffreyi is intermediate between other native Dysphania members (see also Table 1). It is possible that the species may also be found in India (Arunachal Pradesh) and North Myanmar.

Specimens examined ( Fig. 3 ):— BHUTAN. Upper Mo Chu distr. [Punakha distr.]: Gangyvel Chu below Gangyvel , grassy hillside, ca. 3820 m, 27 September 1984, Sinclair & Long 5364 (E-00151629) *. CHINA. Xizang prov.: Kham (Tibet), basin of Yangtse river, Nru-chu natural feature, gravelly substrate, 25 July 1900, Ladygin 371 ( LE, MW) ; Vicinity of Lhasa , July 1939, Richardson 308 ( BM) ; Lhasa , 12000 ft, 5 September 1943, Ludloff & Sheriff 9919 ( BM) ; Lhasa, 1946–1950, Aufschnaiter s.n. ( BM) ; Yunnan prov.: Lichiang [26 48’N 100 16’E, near the city Lijiang], in ruderatis, ca. 2500 m, Mid-September 1914, Schneider 2904 ( G) *; Deqin [Diqing] County, Adunzi , 2700 m, 26 September 1935, Wang Qiwu 70221 ( WUK, original text in Chinese) *; NE of Zhongdian (Chungtien), Nada village , on top of wall, in turf capping, 3360 m, 27 September 1990, Chungtien-Lijiang-Dali Expedition 324 ( E) .

1 Data on label were translated from Chinese (original text). always minute (1–2 µm) and is not mentioned in the analysis.

Figures

FIGURE 1. Holotype of Dysphania geoffreyi (PE-00510980!).

FIGURE 2. Perianth, fruit and seed of D. geoffreyi. A, B) perianth with stout and long simple hairs (sh), simple hairs with concrescent bases (csh), subsessile glands (sg) and scattered glandular hairs (gh); C) pericarp surface; D) seed with remnants of pericarp (p). Voucher specimens:A, C, D) China, Tibet [Xizang prov.], Lhasa, Daxika, 4150 m, 5 September 1965, Yong-tian Zhang & Kai-yong Lang 2663 (PE- 00510980!); B) Bhutan, Upper Mo Chu distr. [Punakha distr.], Gangyvel Chu below Gangyvel, ca. 3820 m, 27 September 1984, Sinclair & Long 5364 (E-00151629).

FIGURE 3. Distribution patterns of D. geoffreyi (asterisks) and D. himalaica (dots).