Benthamia, A. RICH. Benthamia, A. RICH.

Hervouet, Jean-Michel, Descourvières, Pascal, Hermans, Johan & Longou, Ludivine, 2025, Revision of the genus Benthamia A. Rich. (Orchidaceae, Orchidioideae, Habenariinae), Adansonia (3) 47 (11), pp. 171-249 : 174-175

KEY TO THE GENUS BeNThaMIa A. RICH.

1. Spur elongated, cylindrical .......................................................................................................................... 2

— Spur short, scrotiform ................................................................................................................................. 7

2. Leaves reduced to sheaths or not developed at flowering .............................................................................. 3

— Leaves developed at flowering ...................................................................................................................... 4

3. Lip clearly trilobed ................................................................................................. Benthamia praecox Schltr.

— Lip obscurely trilobed ................................................................................................ Benthamia exilis Schltr.

4. Leaf single ................................................................................................................................................... 5

— More than one leaf ...................................................................................................................................... 6

5. Lip trilobed ....................................................................................... Benthamia glaberrima (Ridl.) H.Perrier

— Lip entire ......................................................................................................... Benthamia monophylla Schltr.

6. Leaves 2, rarely 3 .................................................................................................... Benthamia rostrata Schltr.

— Leaves 3 to 6 ...................................................................................................... Benthamia bathieana Schltr.

7. Spur scrotiform or dorso-ventrally flattened ................................................................................................ 8

— Spur a simple hollow at the base of the lip ........................................................ Benthamia boiteaui Hervouet

8. Plants epiphytic ........................................................................................................................................... 9

— Plants terrestrial ......................................................................................................................................... 14

9. Plants more than 45 cm tall ......................................................................... Benthamia majoriflora H.Perrier

— Plant less than 45 cm tall ........................................................................................................................... 10

10. Lip entire or obscurely trilobed .................................... Benthamia erinacea (Cordem.) Hermans & P.J.Cribb

— Lip distinctly trilobed ................................................................................................................................ 11

11. Lobes of lip truncate .................................................. Benthamia lakatoensis Descourv. & Hervouet , sp. nov.

— Lobes of lip not truncate ........................................................................................................................... 12

12. Sepals green, petals white ................................................... Benthamia trifida Hermans & Hervouet , sp. nov.

— Sepals white or off-white ........................................................................................................................... 13

13. Flowers pure white .................................................................................................... Benthamia nivea Schltr.

— Flowers off-white ................................................................ Benthamia corona Hermans & Hervouet , sp. nov.

14. Petals white ............................................................................................................................................... 15

— Petals green or yellow ................................................................................................................................ 16

15. Basal leaf solitary ............................................................................................ Benthamia herminioides Schltr.

— Basal leaves several ........................................................................ Benthamia madagascariensis (Rolfe) Schltr.

16. Leaf solitary ............................................................................................................................................... 17

— Leaves several ............................................................................................................................................ 19

17. Lip calceolate .................................................................................................. Benthamia calceolata H.Perrier

— Lip not calceolate ...................................................................................................................................... 18

18. Leaf linear ................................................................. Benthamia spiraloides (Cordem.) Hermans & P.J.Cribb

— Leaf elliptic or elliptic-lanceolate ..... Benthamia arcuata (H.Perrier) Descourv. & Hervouet , comb. nov., stat. nov.

19. Leaves near middle of stem ........................................................................................................................ 20

— Leaves basal ............................................................................................................................................... 24

20. Leaves 5 or more .................................................................................... Benthamia spiralis (A.Rich.) A.Rich.

— Leaves fewer than 5 ................................................................................................................................... 21

21. Flowers arranged in 3 rows ............................................................................ Benthamia perfecunda H.Perrier

— Flowers not arranged in 3 rows .................................................................................................................. 22

22. Lip with prominent callus ............................................................................... Benthamia melanopoda Schltr.

— Lip lacking a prominent callus .................................................................................................................. 23

KEY TO THE GENUS BeNThaMIa A. RICH. (continuation)

23. Spur ventrally flattened .................................................................................. Benthamia vulcanorum sp. nov.

— Spur scrotiform .............................................................. Benthamia mascula Hervouet & Descourv. , sp. nov.

24. Inflorescence arcuate ........................................................................................... Benthamia bosseri Hervouet

— Inflorescence erect ..................................................................................................................................... 25

25. Lip lateral lobes very short ......................................................................................................................... 30

— Lip clearly trilobed .................................................................................................................................... 26

26. Leaves more than 4 times longer than wide ............................................................................................... 27

— Leaves less than 4 times longer than wide .................................................................................................. 29

27. Leaves erect and regularly alternate .......................................................................... Benthamia flavida Schltr.

— Leaves not alternate ................................................................................................................................... 28

28. Leaves basal, rachis often less than a third of plant height ....... Benthamia litoralis Hervouet & Descourv. , sp. nov.

— Leaves up to rachis, rachis often half of plant height ................................................... Benthamia elata Schltr.

29. Leaves 5 or more ............................................................................................ Benthamia humbertii H.Perrier

— Leaves fewer than 5 ................................ Benthamia latisatis (Thouars) Bytebier. ( La Réunion and Mauritius)

30. Leaves more than 5 cm long, basal or cauline ....................................... Benthamia africana (Lindl.) Hermans

— Leaves less than 5 cm long, basal ....................................................................... Benthamia decaryana sp. nov.