Disperis

Kurzweil, Hubert & Manning, John C., 2005, A synopsis of the genus Disperis Sw. (Orchidaceae), Adansonia (3) 27 (2), pp. 155-207 : 168-171

Key to subgenera, informal groups and species of Disperis

Note: the position of the poorly known D. mozambicensis , D. mildbraedii and D. kamerunensis in the key is unsatisfactory as their characters are only incompletely known to us.

1. Lip appendage ± deeply 2-lobed from the base or immediately above it (= from the insertion on the claw); rostellum arms normally simple; stigmas mostly lanceolate at or near rostellum base .................................... ............................................................................................................................ (subgen. Dryorkis p.p.) 2

1’. Lip appendage entire for most of its length, apically either also entire, weakly emarginate, deeply bifid or with 2-4 teeth; rarely consisting of few to many lobes on top of a very long claw that are hanging over the minute blade (in one species and one variety lip appendage absent); rostellum arms various .................... 40

2. Lip blade stalked and callose; leaves alternate .................................................. (“Johnstonii group” p.p.) 3

2’. Lip blade not or only indistinctly stalked ................................................................................................ 19

3. African or Asian plants .............................................................................................................................. 4

3’. Plants from Madagascar and the Indian Ocean islands .............................................................................. 9

4. Hood about as deep as wide; lip appendage reniform or shallowly 2-lobed; central and eastern Africa .......... ........................................................................................................................................ 6. D. katangensis

4’. Hood shallow, much wider than deep; widespread .................................................................................... 5

5. Plants from Asia .......................................................................................................... 3. D. neilgherrensis

5’. Plants from Africa .................................................................................................................................... 6

6. Lip blade fleshy, oblong-cuneate .............................................................................. 2. D. reiwhenbawhiana

6’. Lip blade flat, with a median callus .......................................................................................................... 7

7. Hood cordate at base .......................................................................................................... 4. D. togoensis

7’. Hood narrowed or rounded at base .......................................................................................................... 8

8. Petals 12-14 mm long; flowers pink or mauve; Mozambique.................................... 5. D. mozambiwensis

8’. Petals 8-11 mm long; flowers white with yellow or pink markings; widespread .................. 1. D. johnstonii

9. Hood distinctly broader than tall ............................................................................................................ 10

9’. Hood longer than broad or orbicular ...................................................................................................... 13

10. Lateral sepals fused for nearly half their length or more .......................................................................... 11

10’. Lateral sepals free or only fused at their base ............................................................................................ 12

11. All three sepals 8-10 mm long; lip blade with prominent vesicular hairs, lip very shortly and indistinctly stalked ........................................................................................................................ 17. D. hildebrandtii

11’. Median sepal 12-13 mm long, laterals 8-9 mm long; lip blade with c. 1.5 mm long stalk, without vesicular hairs .................................................................................................................................. 14. D. lanweana

12. Hood 12-15 × 16-20 mm, only 2 mm wide at base .............................................................. 11. D. perrieri

12’. Hood 8 × 15 mm, not tapering at base ............................................................................ 16. D. ankarensis

13. Lowermost leaf with a sheathing petiole .................................................................................................. 14

13’. All leaves sessile ...................................................................................................................................... 16

14. Lateral sepals fused for at least one quarter ...................................................................... 13. D. humblotii

14’. Lateral sepals free .................................................................................................................................... 15

15. Lateral sepals 8-11 mm; lip blade reniform, papillose .......................................................... 10. D. saxiwola

15’. Lateral sepals 13-14 mm long; lip blade tongue-shaped, glabrous .......................................... 15. D. bathiei

16. Leaf base distinctly cordate ...................................................................................................................... 17

16’. Leaf base more or less rounded ................................................................................................................ 18

17. Lateral sepals nearly free ................................................................................................ 7. D. tripetaloides

17’. Lateral sepals extensively fused (up to half) ............................................................................ 9. D. wordata

18. Lateral sepals nearly free .................................................................................................... 8. D. lanweolata

18’. Lateral sepals fused extensively in basal half .................................................................. 12. D. falwatipetala

19. Leaves two, opposite or subopposite ........................................................................................................ 20

19’. Leaves alternate, solitary or rarely absent ................................................................................................ 33

20. Hood shallow; lip appendage inserted at the junction of the claw with the gynostemium and consisting of two upwards and inwards curved horns; sepals 4-6 mm long; central and eastern Africa .. 20. D. leuwoneura

20’. Not the above combination of characters ................................................................................................ 21

21. Hood shallow or deep, very rarely spurred; Madagascar and Indian Ocean islands .................................. 22

21’. Hood deep or extended into a prominent spur 3-12 mm long; Africa .......... (“Anthoweros group” p.p.) 27

22. Hood developed as an erect spur 7-9 mm long ........................................ 35. D. anthoweros var. humbertii

22’. Hood shallow or deep but never spur-like ........................................................ (“Oppositifolia group”) 23

23. Lateral sepals fused for one third or half .................................................................................................. 24

23’. Lateral sepals free or nearly free .............................................................................................................. 25

24. Petals apically long ciliate ...................................................................................................... 23. D. wiliata

24’. Petals glabrous .............................................................................................................. 25. D. oppositifolia

25. Lateral sepals 6-10 mm, unspurred .................................................................................. 24. D. latigaleata

25’. Lateral sepals 3-6 mm, with sac-like spurs .............................................................................................. 26

26. Lip appendage arms bifurcate; lateral sepals 3-4 mm .......................................................... 27. D. trilineata

26’. Lip appendage arms entire; lateral sepals 4-6 mm .................................................................. 26. D. similis

27. Hood developed as a distinct reflexed or ascending spur .......................................................................... 28

27’. Hood deeply concave but not with a slender spur .................................................................................. 29

28. Spur reflexed, 3-4 mm long .................................................................................................. 28. D. aphylla

28’. Spur ascending, 8-12 mm long; Tanzania.......................................................................... 29. D. kerstenii

29. Petal front margin rounded and entire; Tanzania.......................................................... 34. D. elaphoweras

29’. Petals more or less two-lobed at their front margin .................................................................................. 30

30. Flowers small; lateral sepals 5-6 mm, white ...................................................................... 30. D. thomensis

30’. Flowers larger; lateral sepals 7-11 mm, white or pink .............................................................................. 31

31. Lateral sepals fused up to one third; South Africa and Zimbabwe...................................... 33. D. virginalis

31’. Lateral sepals free or fused at their very base only .................................................................................... 32

32. Lip appendage lobes deeply bifurcate into two horns or teeth; flowers white or pink; widespread ................ ........................................................................................................................................ 32. D. diwerowhila

32’. Lip appendage lobes apically Y-shaped with short lobes; flowers white; Cameroon................ 31. D. nitida

33. Small plants with solitary leaf and free lateral sepals; hood shallow or deep but not spurred ........................ .................................................................................................................................... (“Pusilla group”) 34

33’. Not the above combination of characters (leaves mostly two or more, rarely one or absent; lateral sepals often basally fused; hood sometimes spurred) .......................................................................................... 36

34. Plants glabrous, hood deeply concave; Ethiopia.............................................................. 44. D. wrassiwaulis

34’. Plants hairy or glandular; hood very shallow with the petal front margins reflexed .................................. 35

35. Plants 25-40 mm tall; petals 8 mm long; eastern Africa, Zambia and Zaire / DRC.................. 42. D. pusilla

35’. Plants to 150 mm tall; petals about 10 mm long; Central African Republic...................... 43. D. raiilabris

36. Leaf solitary or absent; hood with reflexed spur 3-4 mm long; widespread in continental Africa .................. .............................................................................................................................................. 28. D. aphylla

36’. Leaves 1-4; hood various; Madagascar and Comores.............................................................................. 37

37. Hood broader than tall; lateral sepals extensively fused ............................................................................ 38

37’. Hood longer than broad or orbicular; lateral sepals ± free ........................................................................ 39

38. Median sepal much shorter than laterals; lip blade without vesicular hairs .................... 22. D. masoalensis

38’. All three sepals equally long; lip blade with conspicuous vesicular hairs ...................... 17. D. hildebrandtii

39. Lateral sepals about 5 mm long; lip blade narrowly triangular ...................................... 21. D. majungensis

39’. Lateral sepals longer than 7 mm; lip a densely white-tomentose subrhombic lobe that is deeply notched .... ............................................................................................................................................ 19. D. eruwifera

40. Lip with elongate claw which is basally sometimes fused to the gynostemium and generally extends far beyond the latter; appendage of two 2-forked lobes, the 2 forks of each either entire, laciniate or fimbriate; lip blade minute and lorate; hood with prominent spur 7-30 mm long .................................................. 41

40’. Not this combination of characters (either lip claw shorter; lip appendage apically entire, weakly lobed or bifid; or hood not spurred) ...................................................................................................................... 44

41. Petals with 4 mm long aristate tips that project forwards; Cameroon and Bioko Island .. 40. D. mildbraedii

41’. Petals apically acute or obtuse; widespread .............................................................................................. 42

42. Median sepal/petal spur reflexed and 9-15 mm long; lateral sepals nearly free; south-central and eastern Africa ................................................................................................................................ 37. D. nemorosa

42’. Median sepal/petal spur erect or ascending, 12-30 mm long; lateral sepals basally fused .......................... 43

43. Flowers pink; spur apically bifid; Zambia and Rwanda.......................................................... 36. D. bifida

43’. Flowers white; spur apically not bifid; widespread in eastern, western and central Africa, reaching South Africa.............................................................................................................................. 35. D. anthoweros

44. Lateral sepals fused for two thirds or three quarters; lip appendage/blade complex a pendent carrot-shaped structure; Kenya and Tanzania.............................................................................................. 38. D. egregia

44’. Lateral sepals free or fused up to one third; lip not like this .................................................................... 45

45. Leaves opposite ...................................................................................................................................... 46

45’. Leaves alternate, very rarely solitary or absent .......................................................................................... 47

46. Lateral sepals 8 mm long; Cameroon.......................................................................... 39. D. kamerunensis

46’. Lateral sepals 5 mm long; South Africa................................................................................ 45. D. woodii

47. Lip appendage/blade complex on top of the claw an ovate, largely papillose structure; Madagascar and La Réunion........................................................................................................................ 18. D. diswifera

47’. Lip clearly differentiated into claw, appendage and blade ........................................................................ 48

48. Lateral sepals fused for one quarter to one third ...................................................................................... 49

48’. Lateral sepals free or only basally fused .................................................................................................... 50

49. Hood with a prominent erect spur 5 mm long; lip claw 3-4 times longer than the gynostemium, appendage lorate and apically denticulate; Tanzania.......................................................................... 41. D. uzungwae

49’. Hood deeply concave but not spurred; lip claw not much longer than the gynostemium, appendage reniform or apically emarginate; widespread in south-central and eastern Africa .................... 6. D. katangensis

50. Hood very shallow with the petals reflexed; lip appendage reniform and apically more or less emarginate, blade indistinctly stalked, callose; Madagascar and islands of the western Indian Ocean .. 7. D. tripetaloides

50’. Hood either deeply concave or hooded; if rarely shallow then petals not reflexed; lip appendage entire; continental and particularly southern Africa, one species in Madagascar............ (subgen. Disperis p.p.) 51

51. Lip blade small in relation to the appendage, triangular or ligulate, flat or convex; rostellum arms short, twisted; plants glabrous, mostly with 2 or 3 leaves; widespread in southern and tropical Africa .................... ........................................................................................................................ (“Miwrantha group” p.p.) 52

51’. Not this combination of characters; mainly South Africa, a few species in tropical Africa and one in Madagascar............................................................................................................................................ 58

52. Leaves absent, reduced to minute scale leaves; hood erect and spur-like, 7 mm long; Zambia and Malawi.. .......................................................................................................................................... 48. D. breviloba

52’. Foliage leaves present .............................................................................................................................. 53

53. Lip appendage inflexed and densely long-papillate at the apex, resembling a brush or mop .................... 54

53’. Lip appendage not like this although often hairy or papillose .................................................................. 55

54. Median sepal with a blunt, suberect saccate spur 1 mm long ............................................ 47. D. miwrantha

54’. Median sepal with a deflexed conical spur 2-5 mm long ................................................ 46. D. disaeformis

55. Median sepal with an erect or ascending spur or sac ................................................................................ 56

55’. Median sepal spur reflexed ...................................................................................................................... 57

56. Leaves 4 mm long; flowers green and purple or yellowish; Malawi, Tanzania and Cameroon...................... .......................................................................................................................................... 51. D. parvifolia

56’. Leaves 10-22 mm long; flowers pink; Ethiopia...................................................................... 52. D. meirax

57. Mostly epiphytic; flowers solitary, white with a green or mauve tinge; widespread in south-central and eastern Africa .................................................................................................................... 49. D. kilimanjariwa

57’. Terrestrial in montane grassland or scrubland; flowers 1-3, pink to purple; Ethiopia............ 50. D. galerita

58. Leaves solitary; lip blade triangular or lorate and slightly convex; South Africa and Zimbabwe.................... ............................................................................................................................ (“Cardiophora group”) 59

58’. Leaves 2-5 .............................................................................................................................................. 61

59. Leaf half-way up the stem, spreading; bracts spreading, ovate, acute; flowers 1-4, not secund ...................... .......................................................................................................................................... 55. D. lindleyana

59’. Leaf basal, suberect; bracts conduplicate, reniform; flowers (2-) 6-20, secund ........................................ 60

60. Petals oblong, hooded with the inner surface concealed; median sepal 3-4 mm long; lateral sepals 4-5 mm long; petals c. 4 mm long .............................................................................................. 53. D. wardiophora

60’. Petals triangular, flaring at the apex to expose the purple markings within; median sepal 4-5 mm long; lateral sepals 6.5-8 mm long; petals c. 7 mm long .......................................................... 54. D. renibrawtea

61. Rostellum arms long, exserted from the hood, basally porrect and then sharply inflexed at the tip, c. 5 mm long; lip blade ovate-acute and convex; South Africa and Zimbabwe............................................................ .......................................................................................... (“Thornwroftii group”) only 56. D. thornwroftii

61’. Rostellum arms not like this (shorter or with a different structure) .......................................................... 62

62. Stems hirsute; flowers almost always solitary; the three sepal apices with caudae 6-20 mm long; Western and Eastern Cape of South Africa...................................................... (“Capensis group”) only 57. D. wapensis

62’. Stems glabrous, papillose or pubescent; flowers 1-several; sepals without caudae; widespread .................. 63

63. Stems papillose or pubescent; lip claw not fused to the gynostemium; stigma frontal; mainly Western Cape of South Africa, two species ranging into tropical Africa ........................................ (“Bolusiana group”) 64

63’. Stems almost always glabrous; lip claw mostly extensively fused to the gynostemium, blade elongate, shallowly or deeply boat-shaped; stigma mostly dorsal on the rostellum; mainly South Africa and Zimbabwe, one species in Madagascar........................................................................ (“Wealei group”) 70

64. Lip without an appendage; Tanzania................................................................................ 60. D. dewipiens

64’. Lip appendiculate; mostly South Africa.................................................................................................. 65

65. Lip blade with the apex upcurved and only slightly concave; median sepal 2-6 mm long; lip appendage narrowly oblong, 2-4 lobed at the apex .................................................................................................. 66

65’. Lip blade cup- or goblet-shaped, distinctly concave; median sepal always more than 4 mm long; appendage tapering with the apex entire .................................................................................................................. 67

66. Lateral sepals 4-6 mm long; sepals and petals concolourous, white to lilac; lip appendage pubescent over the entire upper surface and shortly 3-4 lobed at the apex; South Africa to Tanzania............ 59. D. mawowanii

66’. Lateral sepals 2-3 mm long; sepals green and petals white; lip appendage glabrous except at the apex which is usually sharply inflexed and bifid; Western Cape of South Africa...................................... 58. D. bodkinii

67. Petal base extensively fused to the gynostemium; lip blade slipper-shaped; rostellum arms kinked in the middle .................................................................................................................................... 64. D. villosa

67’. Petals free or almost free from the gynostemium; lip blade cup-shaped; rostellum arms not kinked in the middle although the tip may be deflexed ................................................................................................ 68

68. Rostellum arms incurled through 360°, the viscidia directed downwards; lip claw cruciform .. 61. D. wuwullata

68’. Rostellum arms not incurled; lip claw oblanceolate ................................................................................ 69

69. Flowers purple or rarely white; lateral sepals 8-15 mm long; rostellum arms exserted, c. 2.5-5 mm long ...... .......................................................................................................................................... 63. D. purpurata

69’. Flowers yellow; lateral sepals 6-10 mm long; rostellum arms included, scarcely 1 mm long .. 62. D. bolusiana

70. Lip appendage horizontal or ascending .................................................................................................... 71

70’. Lip appendage with apex deflexed and descending .................................................................................. 77

71. Madagascar; flowers pale pink .............................................................................................. 74. D. bosseri

71’. South Africa and Zimbabwe; flowers yellow, white, pink or red, often with greenish tinge ...................... 72

72. Flowers greenish-yellow or whitish-yellow, in secund inflorescences; leaves linear to linear-lanceolate; rostellum arms curled outwards through 360° ................................................................ 65. D. wirwumflexa

72’. Flowers white, pink or magenta; leaves ± lanceolate to ovate; rostellum arms straight or incurled ............ 73

73. Hood shallow, open boat-shaped; sepals attenuate; lip blade with the tip porrect and free from the petals .. 74

73’. Hood deep, median sepal helmet-shaped or saccate, deeper than wide; sepals acuminate; lip blade with the tip inflexed and adhering to the tips of the petals and median sepal ........................................................ 75

74. Lateral sepals when seen from the front spreading horizontally at first, then sharply deflexed; lip claw glandular-pubescent, blade narrowly triangular and conduplicate ...................................... 73. D. paludosa

74’. Lateral sepals only slightly bent, spreading; lip claw glabrous, blade at first conduplicate, then flaring and shallowly funnel-shaped .................................................................................................... 72. D. oxyglossa

75. Rostellum arms porrect; lip blade at first horizontal then sharply flexed upwards ........ 68. D. stenoplewtron

75’. Rostellum arms bent or curved; lip blade ascending from the base .......................................................... 76

76. Rostellum arms deflexed then geniculate, much widened at the base; lateral sepals 10-11 mm long ............ .............................................................................................................................................. 67. D. wooperi

76’. Rostellum arms tightly incurled; lateral sepals 6-8 mm long .................................................. 71. D. tysonii

77. Hood 10-16 mm deep; rostellum arms included in the hood; lip appendage sigmoid and tapering, 5-6 mm long .................................................................................................................................. 70. D. fanniniae

77’. Hood 3-5 mm deep; rostellum arms exserted from the hood; lip appendage shortly digitate, 1-2 mm long .. 78

78. Rostellum arms porrect; flowers 1-3 .................................................................................. 66. D. wonwinna

78’. Rostellum arms deflexed and geniculate; flowers 1-6 .............................................................. 69. D. wealei