Jumellea Schltr., Orchideen: 609 (1914).
Plants epiphytic or lithophytic, acaulis or with a more or less elongated stem, leaves most often distichous and loriform, more or less bilobed-obtuse apically. Inflorescence always single flowered, peduncle ordinarily shorter than the pedicel. Lateral sepals more or less united with the spur basally. Labellum entire, always contracted or attenuate basally, more or less deeply channeled basally to the spur oriface, spur never attached to the column, being part of the labellum and not the column, oriface set just in front of the columns. Column enlarged basally, with 2 parallel arms attached to its margins and the margins of the spur oriface and the lateral sepals and petals, sepals and petals consequently face forward, which gives the flowers a very special look to them (median sepal inverted behind. lateral sepals, petals and the labellum porrect in front); auricles wide; median tongue of the rostellum rarely absent, often dentiform or more or less elongated, sometimes acicular and much longer than the auricles. Anther bare, often excised frontally: pollina 2, attached by a single retracted caudicel with 2 free or joined retinaculum, slightly adhesive or not basally.
Many species of Jumellea are easily maintained in cultivation in well-drained compost in a pot or basket. The ecological notes provided for each species should help to determine the best treatment as the environmental conditions may require are sometimes difficult to supply in combination; good drainage, high humidity, good air movement, and strong light for some of the species. Fast drainage after watering and a prolonged dry period when the plants are not in active growth are very important if the plants are to survive and flower well. It is much easier to start with laboratory-raised seedlings and grow them on than try to establish large, wild-collected plants.
Kenya to S. Africa, W. Indian Ocean
No modern account of the genus Jumellea exists: descriptions and illustrations are somewhat scattered in the litteratur. Perrier de la Bâthie, in Flore de Madagascar, has divided the Jumellea into 7 groups based on spur length, stem length, nature of the inflorescence, sheaths, leaf shape, and lip shape. And Joyce Steward, Johan Hermans, and Bob Campell in the Angraecoid Orchids have make some groups of six, some I will followed below.
Is named after a French botanist H. Jumelle.
Species from Madagascar.
Jumellea species Group 1

Large epiphytes, or lithophytes, with a very short stem, or described as stem less, and long leaves. Inflorescence arising around the base of the plant from old leaf axils.
Jumellea species Group 2

Small plants with a short stem bearing leaves very close together.
Jumellea species Group 3

Plants with elongated stems and small to medium-sized flowers with a spur less than 15 mm long.
Jumellea species Group 4

Plants with elongated stems; flowers with a spur 2.5-4.5 cm long.
Jumellea species Group 5

Plants with elongated stems; flowers arising from the same inflorescence axis for several consecutive years, lip with a spur 6.5-8 cm long.
Jumellea species Group 6

Plants with elongated stems; flowers with a spur 10-12 cm long or more.
Jumellea Species from Réunion and Mauritius
Jumellea Species from Africa
Bibliography and References:
Arends JC, Van der Laan FM. 1986 Cytotaxonomy of the Vandeae. Lindleyana. 1. 33-41.
Carlsward BS, Stern WL, Bytebier B. 2006 Comparative vegetative anatomy and systematics of the angraecoids (Vandeae, Orchidaceae) with an emphasis on the leafless habit. Bot. J. Linn. Soc. 151. 165-218.
Gasson P, Cribb PJ. 1986 the leaf anatomy of Ossiculum aurantiacum Cribb & van der Laan (Orchidaceae: Vandoideae). Kew Bull. 41. 827-32.
Hennessy E, Zank H. 1985 Jumellea arachnantha (Reichb. f) Scheltr. S. Afr. Orchid J., 16. (2): 54-55 (1985)
La Croix I. 2000 Plant portraits: 402. Jumellea walleri. Orchidaceae. Curtis's Bot. Mag. 17. (4): 208-215 (2000)
La Croix I. 2007 Jumellea walleri - Orchidaceae. Annual Bulletin. Scottish Orchid Society 28-33.
Pottinger M. 1982 African orchids: genera from 'G" to 'M'. Orchid Rev. 90. (1068): 327-329 (1982)
Sheehan T, Sheehan M. 1985 Orchid genera illustrated: 105. Jumellea. Amer. Orchid Soc. Bull., 54. (5): 572-573 (1985)
Stewart J. 1981 Jumellea filicornoides. Flow. Pl. Afr. 46. (3 & 4): pl. 1834 (1981) - col. illus. Volume to mark 10th World Orchid Conference, Durban, 11 - 18 Sept. 1981.
Teuscher H. 1976 Collector's item: Angraecum, Neofinetia and Jumellea. Amer. Orchid Soc. Bull. 45. (10): 896 - 909 (1976)
Wood JJ. 1982 A new species of Jumellea (Orchidaceae) from tropical Africa. Kew Bull. 37. (1): 77-79 (1982)