Distribution Map
Description (Barlow 1993)
Decaisnina zollingeri (Tieghem) Barlow, comb. novo
Amylotheca zollingeri Tieghem, Bull. Soc. Bot. France 41 (1894) 264. - Type: Zollinger s.n. (holo P; iso L), Celebes, Macassar.
For description and additional synonymy see Danser, Bull. Jard. Bot. Buitenzorg III, 11 (1931) 252. Apart from the strongly angular stems, Decaisnina zollingeri has few specialized characters, and thus presents a relatively generalized facies for the genus. The species can be identified by its combination of characters of the stem internodes, which are buff-coloured and terete when older, with slightly enlarged nodes, but dark or greenish when younger, flattened towards the apex and usually 4-ridged, with 2 ridges forming sharp edges and usually 2 forming crests on the flattened faces; the leaves, which are usually very weakly bifacial but dull on both sides and truncate or contracted at base with a short petiole 2-4(-10) rom long; and the corollas, which are 22-27 rom long and usually shortly inflated at the base prior to anthesis. The inflation of the corolla base in D. zollingeri is not consistently visible in the specimens examined (see note under D. stenopetala). The flower colour is described as green or yellow, sometimes with red in the lower part.
Decaisnina zollingeri is distributed widely in southeastern Malesia, from Java (Kangean Archipelago) to Celebes, Moluccas, Lesser Sunda Is (Alor) and western New Guinea (Fig. 9; 16 collections seen), at low elevations from sea level to 620 m. Additional collections seen in the present study have extended the known range to the Lesser Sunda Islands and to western New Guinea. Habitat details are poorly known; the species has once been recorded as parasitic on Albizia.
The species is probably closely related to D. stenopetala and D. sumbawensis, with both of which it is geographically sympatric. The three species share very similar inflorescence and flower characters (for differences see note under D. stenopetala). Decaisnina zollingeri is possibly also related to D. cumingii, with which it is approximately parapatric (for similarities and differences see note under D. cumingii). Having an arc-like area which straddles Charles's Line, D. zollingeri occupies a geophysically turbulent part of the Malesian region in which there has been much recent change in landform (Audley-Charles, 1981). If D. zollingeri has originated in situ, it is possibly a relatively young species.
In resolving the species limits, a number of
collections have been referred to taxa differently from their
placement by Danser (1931) and Barlow (1974). In revising New
Guinean taxa, I suggested that D. zollingeri was con specific
with D. stenopetala (Barlow, 1974), but the additional
collections seen in the present study have confirmed the status
of the two as distinct but probably closely related species. Specimens
from western New Guinea formerly referred by me to D. stenopetala
have been found variously to be representative of D. stenopetala,
D. sumbawensis or D. zollingeri.
Illustrations
Decaisnina zollingeri (as Amylotheca zollingeri). A - inflorescence. B - flower in bud. C - flower. D - fruit. From Danser (1931).
Photographs
Decaisnina zolingeri
updated 20 January 2007