Stipa sect. Regalia

Zhang, Yue, Zhang, Xie-Yong, Zhang, Chao, Chen, Wen-Li & Zhu, Shi-Xin, 2023, Stipa baxoiensis (Stipeae, Poaceae), a new species from Qinghai-Tibet Plateau, China, Phytotaxa 597 (4), pp. 280-286 : 284-285

Key to the species of Stipa sect. Regalia in China

1. Panicles contracted and panicle branches straight..............................................................................................................................2

- Panicles lax and panicle branches flexuous........................................................................................................................................6

2. Awn column with hairs up to 1 mm long ...........................................................................................................................................3

- Awn column with hairs 1.5–4 mm long .............................................................................................................................................4

3. Ligules of basal leaves 4–6 mm, leaf blades scabrous ..................................................................................................... S. regeliana

- Ligules of basal leaves 0.3–1.6 mm, leaf blades glabrous .................................................................................................. S. dickorei

4. Glumes 9.5–13.5 mm, with 2–3 mm long-pointed; awn 1.5–1.8(1.9) cm .................................................................. S. basiplumosa

- Glumes 6–9 mm; awn (2.1) 2.2–2.7 cm ..............................................................................................................................................5

5. Base of panicles enclosed by uppermost leaf sheaths; leaf sheaths and adaxial surface of blades glabrous or scabrous.................... ................................................................................................................................................................................... S. subsessiliflora

- Panicles exserted from uppermost leaf sheaths; leaf sheaths and adaxial surface of blades hirsutulous........................ S. baxoiensis

6. Adaxial surface of leaf blades smooth, glabrous; panicle branches ascending, without cushion in axils..........................................7

- Adaxial surface of leaf blades scabrid or hairy; panicle branches spreading, with cushion in axils..................................................8

7. Lemma 6.3–8.5 mm long, awn 15–26 mm long................................................................................................... S. aliena var. aliena

- Lemma 9–12 mm long, awn 23–30 mm long............................................................................................. S. aliena var. macrocarpa

8. Leaf sheaths and adaxial surface of leaf blades scabrous....................................................................... S. penicillata var. penicillata

- Leaf sheaths and adaxial surface of leaf blades hirsute............................................................................... S. penicillata var. hirsuta