Genus Mediocalcar

Mediocalcar J.J.Sm.,
Bull. Inst. Bot. Buitenzorg 7 (1900) 3

Sympodial epiphytic or terrestrial plants. Pseudobulbs present, consisting of one internode. Because of vegetative bud displacement new shoots often arise above the base of the pseudobulb, without a subtending cataphyll, resulting in a sympodium with superposed pseudobulbs (but often with a few narrow, rhizomatous internodes between the pseudobulbs). Leaves 1-6, apical on the pseudobulb, without sheathing base, glabrous, dorso-ventrally flattened or almost terete, articulate, duplicate, leathery. Inflorescence basal (heteranthous) or terminal (synanthous), carrying a single flower, often occurring in pairs. Flowers small, urn-shaped to obliquely globose, resupinate or not, (orange-)red or yellow, often with contrasting apices. Sepals connate. Petals free, much narrower than the sepals. Lip spurred or not, not mobile. Column-foot present. Pollinia 8, solid-waxy, caudicles present, stipe absent, viscidium absent.

Sulawesi, Moluccas, New Guinea, east to Samoa (excl. New Caledonia). About 15 species; in New Guinea 15 species.

Epiphytes in montane forest, at higher altitudes also terrestrial in ground moss and on mossy rocks. Some species are locally very common.

Few genera in New Guinea are as distinctive as Mediocalcar, with its brightly coloured, shiny, urn-shaped flowers, which have a most un-orchid-like appearance. They are almost certainly pollinated by birds, but this has yet to be confirmed by observations in the field. The statement in Prigeon et al. (2005: 564) that flowers of Mediocalcar are thought to mimic those of Vaccinium and other Ericaceae is disproved by the fact that the flowers of Mediocalcar contain nectar and that New Guinea Vacciniums do not have such brightly coloured flowers as Mediocalcar. In other words, Mediocalcar flowers offer an award and they have no model, so the term 'mimic' seems ill-chosen.

The nearest relative is undoubtedly Epiblastus, a genus with superficially similar flowers, in which the sepals are not connate, however (Schuiteman, 1997). This sister group relationship was recently confirmed by molecular work of Ng Yan Peng (see cladogram in Pridgeon et al. 2005: 531).

Schlechter and J. J. Smith recognised three, respectively two sections within the genus, but these do not correspond to natural groups (Schuiteman, 1997).

A key to the species of Mediocalcar is here included in the Text Key module (click on the Text Key icon in the Navigator window, click on Find at the bottom of the text Key window and type Mediocalcar).

Most species are of easy cultivation under permanently cool and humid conditions.

Species included on this CD-ROM:
Mediocalcar agathodaemonis
Mediocalcar arfakense
Mediocalcar bifolium
Mediocalcar brachygenium
Mediocalcar bulbophylloides
Mediocalcar congestum
Mediocalcar crenulatum
Mediocalcar decoratum
Mediocalcar geniculatum
Mediocalcar papuanum
Mediocalcar paradoxum subsp. latifolium
Mediocalcar paradoxum subsp. robustum
Mediocalcar pygmaeum
Mediocalcar stevenscoodei
Mediocalcar subteres
Mediocalcar umboiense
Mediocalcar uniflorum
Mediocalcar versteegii
Mediocalcar versteegii subsp. amphigeneum
Mediocalcar versteegii subsp. intermedium