Pothoidium Schott sec CATE Araceae, 2009

Schott 1857. Oesterr. Bot. Wochenbl.. 7: 70


Distinguishing Features

Evergreen, climbing hemiepiphytes; leaves distichous; petiole entirely flattened, resembling blade; leaf blade much shorter than petiole, midrib absent, fine venation parallel; inflorescences several, in terminal branching system, spathe often absent; flowers apparently usually unisexual, sometimes bisexual, perigoniate with 6 free tepals. Differs from Pothos in having 1-locular ovaries and flowering shoots terminating in a branching system of spadices and often functionally unisexual.

Pothoidium is similar to Pothos repens but differs in being functionally dioecious, by the branching inflorescences, and by its unilocular ovary and solitary ovule. Pothoidium has functionally unisexual spadices arranged seemingly in panicles and maturing sequentially. The structure of the fertile shoots is not yet clearly understood; however, it is possible that they are developed by the reduction of all the leaves of a leafy fertile shoot system to minute prophylls and cataphylls and that the panicle-like synflorescence is hence to be regarded as an aggregate structure. Pothos repens and Pothoidium are vegetatively almost identical. Depauperate flowering specimens of Pothoidium greatly resemble robust plants of Pothos repens. Interpretation of Pothoidium inflorescences suggests that P. lobbianum is functionally dioecious. “Male” spadices have flowers with prominently visible anthers and an apparently sterile ovary. “Female” spadices have flowers with a large unilocular fertile ovary and no stamens. Flowers of Pothos species are always bisexual with a 3-locular ovary.


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