Habenaria sect. Spathaceae

Batista, João A. N., Ferreira, Vera L., Alves, Camila I. G. & Stehmann, João R., 2022, A new species of Habenaria (Orchidaceae, Asparagales) and a checklist of Orchidaceae from limestone outcrops of Brazil, European Journal of Taxonomy 828, pp. 16-44 : 34

Key to the species of Habenaria sect. Spathaceae

1. Flowers completely green; pedicellate ovary 19–25 mm long; pedicel 5–6 mm long, shorter than the ovary; rostellum mid-lobe completely held between the anther loculi ............................................... ............................................................................................................. H. karstica J.A.N.Bat. sp. nov.

– Sepals green, petals and lip white or yellowish; pedicellate ovary (23–) 30–115 mm long; pedicel 9–95 mm long, approximately the same size or longer than the ovary; rostellum mid-lobe mostly held beyond the anther loculi ............................................................................................................ 2

2. Spur shorter than 6 mm ..................................................................................................................... 3

– Spur 24–90 mm long ........................................................................................................................ 4

3. Spur scrotiform, 2.5–3.5 mm long; petal anterior segment and lip lateral segments at least half the length of the petal posterior segment and lip median segment, respectively ..................................... ...................................................................................................................... H. orchiocalcar Hoehne

– Spur obovate, 4–6 mm long; petal anterior segment and lip lateral segments less than half the length of the petal posterior segment and lip median segment, respectively .................. H. heringeri Pabst

4. Corolla yellowish; lateral sepals obliquely oblong; petal posterior segment oblanceolate to spatulate, largest width at the apical third; petal anterior segment 0–1.1 mm long; anther canals ca 5 mm long, parallel; pollinaria separate; stigma lobes with a prominent margin forming a keel .......................... ............................................................................................................................. H. anisitsii Kraenzl.

– Corolla white; lateral sepals obliquely ovate to lanceolate; petal posterior segment not oblanceolate or spatulate, largest width at the middle; petal anterior segment 0–20 mm long; anther canals 1.5– 3 mm long, convergent towards the apices; pollinaria joined by the viscidia; stigma lobes without a prominent margin, not forming a keel .............................................................................................. 5

5. Petals posterior segment rhombic to asymmetricaly trullate ................... H. jaguariahyvae Kraenzl.

– Petals posterior segment lanceolate to narrowly elliptic .................................................................. 6

6. Anterior segment of the petal conspicuous, at least half or more of the length of the posterior segment ..................................................................................................................... H. trifida Kunth

– Anterior segment of the petal absent, reduced to a tooth-like projection or less than half the length of the posterior segment ................................................................................ H. curti-bradei Hoehne