13. Taraxacum sect. Atrata Kirschner & Štepánek, Fl. China. 20-21: 314. 2011.
黑蒲公英组 hei pu gong ying zu
Type: Taraxacum subglaciale Schischkin.
Plantae alpinae vel subnivales graciles, foliis plerumque indivisis, lobulatis, lineari-lanceolatis vel oblongo-lanceolatis, scapis plerumque glaberrimis, phyllariis involucralibus exterioribus non imbricatis vel inconspicue imbricatis, anguste lanceolatis usque lanceolatis, plerumque in parte media latissimis, subobtusis, planis vel callosis, raro minute corniculatis, paucis vel mediocriter numerosis (7 ad 15), atro-viridibus vel obscure viridibus, albo- vel pallidius marginatis, marginibus distinctis vel inconspicuis, 0.1-0.6 mm latis, glabris vel raro sparsissime ciliatis, phyllariis interioribus planis vel interdum callosis, acheniis plerumque 4-5.5 mm longis (pyramide inclusa), omnino laevibus vel raro sublaevibus et tuberculis sparsis minutissimis in parte superiore praeditis, pyramide carentibus vel in pyramidem indistinctam, raro late conicam sensim abientibus, rostro crassiusculo disrumpente 1.5-5(-7) mm longo, pappo albo-lutescente 4-7 mm longo.
Plants delicate, usually glabrous to subglabrous. Petiole unwinged; leaf blade usually narrow, undivided or shallowly lobed. Capitulum often nodding after anthesis. Outer phyllaries 7-15, blackish green to dark green, ± of equal length, appressed, loosely appressed, or rarely erect, narrowly lanceolate to lanceolate, usually broadest in middle, almost unbordered to bordered, margin usually glabrous but seldom sparsely ciliate, apex without a horn but sometimes callose. Ligules yellow, lilac, pinkish to violet. Achene usually grayish straw-colored brown to blackish brown, (3.9-)4-5(-5.7) × 0.8-1 mm; body smooth or less often sparsely minutely tuberculate above, cone absent or achene body gradually narrowing into an indistinct cone, cone (when developed) broadly conical to conical and 0.4-0.8 mm; beak 1.5-5(-7) mm, ± thick, easily breaking off. Pappus yellowish white or white, 4-7 mm.
About 15 species: C Asia; five species (one endemic) in China.
Taraxacum sect. Atrata has a center of diversity in NW China (W Xinjiang), Kazakhstan, Kyrgyzstan, NW Mongolia, and perhaps elsewhere in C Asia.
Taraxacum sect. Oligantha is the closest section to T. sect. Atrata but differs from it in having densely hairy scapes, imbricate and hairy outer phyllaries (often hairy on adaxial and/or abaxial surfaces and ciliate) of paler color, outer phyllaries with a blackish corniculate apex, achene beak very thick (not caducous), and pappus fragile. Another similar taxon, T. glabrum of T. sect. Glabra, differs in the well-developed distinctly narrower cone and thin beak.
In addition to the species given below, there is another name, Taraxacum alpigenum Dshanaëva (Fl. Kirgizsk. S.S.R. 1: 116. 1967), based on the material from a border range between W Xinjiang and Kyrgyzstan (Torugart Range). We have not seen the original material, and the protologue does not give enough facts to compare the name with the other members of the section (with the exception of the achene characters). If it proves to be a separate species, it should be included in the Chinese flora.