|
|
Notes on the Amazonian genus Alloschemone Schott (Araceae—Monsteroideae—Anepsiadeae)
Alistair Hay, Maria de Lourdes da Costa Soares, & Benjamin Gorfer
ABSTRACT
Aspects of the morphology of the still inadequately known Amazonian genus Alloschemone Schott are discussed. It is noted that these nomadic climbing plants appear only to develop epigeal flagelliform shoots, in search of another host tree to climb, from near the ground. It is recorded and illustrated that the pinnatisect leaf blades are marginally dissected and never perforate, in contrast to the intra-marginally divided leaves in the related tribe Monstereae. The unique laminar outgrowths in the sinuses between the lobes of the leaf blade are commented upon, and it is speculated that they may represent vestiges of a more complex ancestral leaf blade type. The seeds are briefly described and illustrated for the first time, noting the conspicuous presence of endosperm. Taxonomic and nomenclatural considerations include noting that the name of the type species, Alloschemone occidentalis, which has been almost universally attributed to Engler & K.Krause, was validated earlier by Baillon. The typification of A. occidentalis (Poepp.) Baill. is discussed, noting that the ‘holotype’ and ‘isotype’ cited by Bogner et al. in their 2001 revision of the genus are better treated as the lectotype and isolectotype, which are accordingly designated here. It is concluded that the second described species, Alloschemone inopinata Bogner & P.C.Boyce, can be viewed more plausibly as a variant within A. occidentalis and it is placed into the latter’s synonymy, leaving Alloschemone monotypic
KEYWORDS:
Marginal dissection, proleptic growth, shoot organisation,, endosperm, Baillon