Family Orchidaceae Subfamily Epidendroideae

Family Orchidaceae Subfamily Epidendroideae

Epidendroideae Lindl., Coll. Bot., App. (1821). Type genus: Epidendrum L.

Synonyms:

  • Neottioideae Lindl., Coll. Bot., App. (1821). Type genus: Neottia Sw.
  • Malaxidoideae Burnett, Outlines Bot. (1835) 461, as Subtypus Malaxidae. Type genus: Malaxis Solander ex Sw.
  • Limodoroideae Burnett, Outlines Bot. (1835) 461, as Subtypus Limodoridae. Type genus: Limodorum Sw.
  • Vandoideae Endl., Gen. Pl. (1837) 196. Type genus: Vanda R.Br.
  • Arethusoidae Endl., Gen. Pl. (1837) 196, 216. Type genus: Arethusa L.
  • KerosphaeroideaeGaray, Bot. Mus. Leafl., 19 (1960) 87, nom. superfl.
  • Tropidoideae (Pfitzer) Szlach., Fragm. Fl. Geobot. Suppl. 3 (1995) 35. Type genus: Tropidia Lindl.

Sympodial or monopodial terrestrials, lithophytes or epiphytes, glabrous or hairy, herbaceous. Roots branched or not, usually stout, rarely slender and wiry, usually with velamen (absent in some terrestrials and all taxa without chlorophyll). Rhizome usually cylindrical, sometimes with tubular scale leaves. Stems in tufts or not, swollen as pseudobulbs or cylindrical and reed-like or compressed, rarely with woody a or branched stems, or stem a corm and underground; pseudobulbs, if present ovoid or obovoid, cylindrical fusiform, club-shaped, conical, sometimes compressed or angular. Leaves usually present. duplicate, in mycoheterotrophic taxa scale-like without chlorophyll, usually distichous, dehiscent, leathery, fleshy, or less often thin-textured, simple, articulated or not; leaf sheath present or not; petiole present or not. Inflorescence lateral or less often terminal, 1- to many-flowered, raceme, a spike, or a panicle. Median sepal free, rarely adnate to the lateral sepals. Lateral sepals free or less often connate; mentum often present. Lip simple, lobed or not, with or without a spur, without or with calli or ridges, warts, hairs, or a farinose callus, hinged or immobile on the base of the column or on the apex of the column foot, with nectar or not; spur absent or present, saccate to cylindrical or club-shaped, sometimes inside with calli or hairs. Column usually glabrous, winged or not; column foot present or not; anther incumbent, rarely erect (Tropidia), terminal on the column; pollinia 2, 4, 6, or 8, sometimes superposed, usually hard and waxy, in some genera soft and mealy either attached directly to a viscidium or by 1 or 2 tegular stipes to 1 or 2 well-developed viscidia; stigma usually a sunken pit below a ridged, 2- or 3-lobed rostellum. Fruit a capsule, dehiscent by longitudinal slits; seeds thread-like, fusiform or rarely with a winged testa.
(after Cribb 2005)


Subfamily Epidendroideae is almost ubiquitous and is especially abundant in the tropics and subtropics, is less abundant in temperate regions; very few species occur within the Northern polar circle and it is absent in Antarctica and in deserts. Bulbophyllum, Eulophia, Oeceoclades, and Polystachya occur in the tropics of all continents, but have most species in Eurasia. Tropical Asia, Australia, and the Pacific have different genera of this subtribe compared with Africa and the islands in the Indian Ocean, with very few species occurring in both regions (e.g. Bulbophyllum longiflorum, Calanthe sylvatica and Oberonia disticha). The highest endemism at generic level is found in Madagascar (32%) at species level in New Guinea (between 90 and 95%).

  • Cameron, K.M. Vanilloideae, in A.M. Pridgeon, P.J. Cribb, M.W. Chase & F.N. Rasmussen (edit.), Genera Orchidacearum Vol. 3 (2003) 281-285.
  • Cameron, K.M., Chase, M.W., Whitten, W. M., Kores, P.J., Jarrell, D. C., Albert, V.A., Yukawa, T., Hills, H. G., and Goldman, D. H., A phylogenetic analysis of the Orchidaceae: evidence from rbbcL nucleotide sequences. American Journal of Botany, 86 (1999) 208-24.
  • Chase, M.W., Cameron, K.M., Barrett, R. L., and J.V. Freudenstein, DNA data and Orchidaceae systematics: a new phylogenetic classification. In K.W. Dixon, S.P. Keil, R.L. Barrett, and P.J. Cribb (edit.), Orchid conservation (2003) 69-89.
  • Cribb, P.J. Subfamily Epidendroideae. In A.M. Pridgeon, P.J. Cribb, M.W. Chase & F.N. Rasmussen (edit.), Genera Orchidacearum Vol. 4 (2005) 3.
  • Dressler, R.L. The orchids: natural history and classification (1981).
  • Dressler, R.L. Phylogeny and classifcation in the orchid family (1993).
  • Szlachetko, D.L. Gynostemia Orchidalium III. Acta Botanica Fennica 176 (2003) 1-311.
  • Family Orchidaceae
  • Subfamily Epidendroideae

Subfamily Epidendroideae, with c. 18,000 species in 650 genera, is by far the largest subfamily of the family Orchidaceae.


ARTIFICIAL KEY TO THE TRIBES OF THE SUBFAMILY EPIDENDROIDEAE IN NEW GUINEA

1a. Anther erect, not incumbent, with the viscidium apical == Tropidieae
1b. Anther incumbent, with the viscidium pointing to the front, or viscidium absent == 2

2a. Plants usually without chlorophyll. Corms or pseudobulbs absent; sometimes tubers present. Leaves not articulate, or with scale leaves. Roots without velamen == 2
2b. Plants with chlorophyll. Corms or pseudobulbs often present. Leaves articulate. Roots with velamen == 4

2a. Pollen in monads or tetrads == Neottieae
2b. Pollen united in entire or sectile pollinia, not in monads or tetrads == 3

3a. Column winged and more than half as long as the petals. Plants without chlorophyll, not green. Seeds thread-like, c. 0.15 cm long == Gastrodieae
3b. Column not winged; much less than half as long as the petals, or when the column is wingend and more than half as long as the petals the plants have chlorophyll and are green. Seeds usually shorter than 0.15 cm == Nervilieae

4. Pollinia without accessory structures or with minute viscidia == 5
4b. Pollinia with one or more accessory structures; viscidia absent or if present not minute == 6

5a. Column foot present. Silica bodies spherical or absent. Seeds covered with fine warts that make the seed appear velvety == Dendrobieae
5b. Column foot absent. Silica bodies conical. Seeds with either not-twisted, elongate cells with elevated margins or with narrow, twisted cells that cover nearly the complete length) == Malaxideae

6a. Stipe present == 7
6b. Stipe absent == 8

7a. Plants without pseudobulbs, usually monopodial. Pollinia usually 2, but also 4 or 8. Silica bodies conical == Vandeae
7b. Plants with pseudobulbs, usually sympodial. Pollinia 2 or 4. Silica bodies spherical == Cymbidieae

8a. Plants terrestrial. Pollinia 2, always hard. Silica bodies not conical == Collabieae
8b. Plants usually epiphytic. Pollinia 2, 4, or 8, sometimes soft. Silica bodies conical or spherical == 9

9a. Column to the apex often widened, winged or hood-like, without a column foot. Caudicles often massive. Silica bodies conical == Arethuseae
9b. Column to the apex not widened, mostly with a column foot. Caudicles not as above. Silica bodies spherical == Podochileae


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Family Orchidaceae Subfamily Epidendroideae

Bulbophyllum xyphoglossum J.J.Verm., de Vogel & A.Vogel flower, front view, photo E.F. de Vogel, Nat. Cap. Bot. Gard. Port Moresby