Prev Genus: Genus Dendrobium section Microphytanthe
Next Genus: Genus Dendrobium section Phalaenanthe
Genus Dendrobium section Pedilonum
Dendrobium sect. Pedilonum Blume, Tab. Pl. Jav. Orchid., in Clavis generum (1825). Type species: Dendrobium secundum (Blume) Lindl. (basionym: Pedilonum secundum Blume).
Synonyms:
- Genus Dendrobium sect. Dendrocoryne Lindl., Edwards's Bot. Reg. 28 (1842) Misc. 76, nom. invalid., not Lindl. 1844. Type species: Dendrobium compressum Lindl.
- Genus Dendrobium sect. Eudendrobium subsect. Pedilonum (Blume) Pfitzer in Engl. & Prantl, Nat. Pflanzenfam. II, 6 ( 1889) 174. Type species: Dendrobium secundum ( Blume) Lindl. Basionym: Pedilonum secundum Blume).
- Genus Dendrobium sect. Platycaula Kränzl. .in Engl., Pflcmzenr., IV. 50. II. B. 21 (1910) 266. Type species: Dendrobium platycaulon Rolfe.
- Genus Dendrobium sect. Platycaulon SchItr. in K.Schum. & Lauterb. Nachtr. Fl. Deutsch. Schutzgeb. Südsee (1905) 150. (‘Platybulbon'). Type species: Dendrobium lamellatum (Blume) Lindl. (basionym: 0nychium lamellatum Blume).
- Genus Dendrobium subgen. Pedilonum (Blume) Kränzl. in Engl., Pflanzenr. IV. 50. II. B. 21 (1910) 96. Type species: Dendrobium secundum (Blume) Lindl. (basionym: Pedilonm secundum Blume).
- Genus Dendrobium sect. Secunda Kränzl. in Engl., Pflanzenr. IV. 50. II. B. 21 (1910) 97. Type species: Dendrobium secundum ( Blume) Lindl. (basionym: Pedilonum secundum Blume).
- Genus Eurycalllis M.A.Clem. & D.J.Jones, Orchadian 13 (2002) 490. Type species: Eurycalllis lamellatus (Blume) M.A.Clem. & D.L.jones (basionym: 0nychium lamellatum (Blume) Lindl.).
- Genus Pedilonum (Blume) Blume, Bijdr. (1825) 320. Type species: Pedilonum secundum Blume.
- Genus Pedilonum sect. Platycaulon (Schltr.) Brieger in Schltr., Orchideen ed. 3, 1 (1981) 685. Type species: Pedilonum lamellatum (Blume) Brieger (basionym: Onychium lamellatum Blume).
- Genus Pedilonum sect. Sanguinolenta Brieger in Schltr., Orchideen ed. 3, 1 (1981) 681. Type species: Pedilonum sanguinolentum (Lind i.) Brieger (basionym: Dendrobium sanguinolentum Lindl.).
NEEDS REVISION: Most species formerly included in Dendrobium sect. Pedilonum Blume are now included in Section Calyptrochilus and the description here and in the latter section must be adjusted.
Epiphytes. Roots glabrous or verrucose. Rhizomes short to elongated. Stems cane-like, clustered, fleshy, elongated, sometimes laterally flattened, fleshy, many-leaved. Leaves short lasting; leaf sheath tubular. Inflorescences lateral or subterminal, mainly from the upper part of the stem, racemose or 1-flowered, usually short and dense. Flowers small to medium-sized, resupinate or not, long-lived (sometimes up to six months), often brightly coloured. Sepals not connate; mentum elongate, often spur-like, parallel with the ovary. Lip not mobile, entire, with a long narrow base; Lip on the apex of the column foot or (less often) adnate to it, entire or weakly 3-lobed; basal part often linear and with a V-shaped callus; midlobe sometimes with indistinct and irregular ridges or at the base with a laterally flattened callus, otherwise without keels or calli. Viscidium soft, distinct.
NEEDS REVISION: Burma, Thailand, Indochina, Indonesia, the Philippines, Papua New Guinea, Solomon Islands, Vanuatu, Fiji, Tonga, Samoa. About 150 species; in New Guinea about 3 species.
NEEDS REVISION: Epiphytes in lowland and montane to subalpine forest. At high altitutes also terrestrial or lithophytic. From sea-level up to about 4000 m altitude.
- Family Orchidaceae
- Subfamily Epidendroideae
- Tribe Dendrobieae
- Subtribe Dendrobiinae
- Genus Dendrobium
- Section Pedilonum
- Lavarack, B., W. Harris & G. Stocker. 2000. Dendrobium and its relatives. Timber Press, Portland, Oregon.
NEEDS REVISION: Dendrobium sect. Pedilonum Blume in the earlier sense contained some of the most colourful of all flowering plants. Almost any colour of the spectrum can be observed in representatives of this section, including blue, violet, green, and scarlet. While sect. Pedilonum is rather uniform in the shape of the flowers, all having a simple lip with a long narrow base. In the present sense, it is in New Guinea represented by only 3 species, all with a wide distribution. Most authors, ourselves included, used to distinguish three or four sections: Pedilonum sensu stricto, Calyptrochilus, Oxyglossum, and Cuthbertsonia. The last two were merged by Reeve & Woods in their masterly revision of sect. Oxyglossum. In the course of preparing the CD-ROM Orchids of New Guinea Vol. 2 (2001) our doubts about the possibility to distinguish these sections became wide awake when we tried to prepare a key to the sections that really worked. This proved to be an impossible task.
Section Calyptrochilus was supposed to differ from Pedilonum by the hood-like inflexed apex of the lip, which is often pleated and more or less distinctly toothed or fimbriate. There is, however, a complete series of intermediates from species with a flat lip apex to those with upright margins, and finally to those with a really hooded apex. The overview picture on the page of Dendrobium sect. Calyptrochilusshould prove this point. Where does Pedilonum end and Calyptrochilus start?
Section Cuthbertsonia was even more weakly defined: the only distinguishing feature being the dwarf habit of the plants in combination with the relatively large flowers produced singly or in pairs. The flowers are not essentially different from such Pedilonum species as Dendrobium pseudoglomeratum and Dendrobium andreemillarae, and an even more dwarf habit is seen in Dendrobium leucocyanum, an undisputed Pedilonum.
Section Oxyglossum, if we excluded sect. Cuthbertsonia, consisted of dwarf plants characterised by the very sharply tipped labellum and the usually (but not always) distinctly angular to winged ovary. Again, these character states were in our opinion merely extremes in a continuous series. We refer to the same picture as above.
Molecular studies later confirmed these doubts and demonstrated that 2 clades exist with superficially similar flowers: a maily Asian clade, Pedilonum and a maily Australasian clade, Calyptrochilus.
Dendrobium sect. Pedilonum in New Guinea contains 3 species:
Dendrobium hasseltii
Dendrobium platygastrium
Dendrobium secundum
Sponsored Ads
Genus Dendrobium section Pedilonum
Dendrobium platygastrium Rchb.f., habit, photo P. O'Byrne, based on O'Byrne D230
Genus Dendrobium section Pedilonum
Dendrobium platygastrium Rchb.f., flower, photo Roy. Bot. Gard. Edin., based on Edinburgh cult. 691491