5. Sect. Biflores A.D.Hall ex Veldkamp & Zonn. in Pl. Syst. Evol. 298(1): 89 (2012)

Type:— Tulipa biflora Pall. in Reise Russ. Reich. 3(2): App. 727 (1776).

Identification key for the species of sect. Biflores distributed in Uzbekistan

1. Upper part of stem and peduncle pubescent (except T. biflora and T. sogdiana), with a short style; flower is whitish with yellow blotch; plants of plains, foothills and mid-mountains, up to 2400–2500 m .......................................................................................2

– Upper part of stem and peduncle glabrous, with a long style; flower is pale yellow or whitish; plants of high mountains, above 2400–2500 m ......................................................................................................................................................................................6

2. Filaments glabrous. Grows in Kyzylkum and adjacent arid plains ...............................................................................1. T. sogdiana

– Filaments with a ring of hairs at the base and wispy hairs along their length....................................................................................3

3. Bulb tunic papery; stem and peduncle glabrous; filaments bearded at the base. Grows in Ustyurt plateau.................... 2. T. biflora

– Bulb tunic coriaceous or thin coriaceous; filaments with wispy, white hairs along the length. Grows in arid plains, Tian-Shan and Pamir-Alay mountains........................................................................................................................................................................4

4. Leaves widely spaced, commonly much shorter than the flower.................................................................................3. T. buhseana

– Leaves more or less widely spaced, commonly longer than the flower.............................................................................................5

5. Bulb tunic tough and dark brown, at the upper part densely clothed with long silky hairs. Grows in Pamir-Alay mountains ………………………………………………………. 4. T. turkestanica

– Bulb tunic tough reddish-brown or pink, densely lined with cobwebby hairs increasing to a tuft at the apex. Grows in West TianShan mountains .......................................................................................................................................................5. T. bifloriformis

6. Bulb tunic finely cobweb-hairy on the inner surface; leaves set closely, commonly opposite; flower whitish with yellow blotch, outer segments dingy violet on the back; filaments with hairs at the base; anthers violet. Grows in Hissar range............................. .................................................................................................................................................................................. 6. T. orithyioides

– Bulb tunic covered with hairs in the upper part; leaves rather widely spaced; flower bright yellow; outer segments brownish or greenish on the back; filaments pubescent over the entire surface; anthers yellow...........................................................................7

7. Bulb tunic usually light-brown or brown, papery, glabrous or covered with few straight, adpressed, white hairs at tip .................... .................................................................................................................................................................................. 7. T. dasystemon

– Bulb tunic black to tawny, thin coriaceous, densely lined with woolly hairs at tip ......................................... 8. T. dasystemonoides