Tuesday, June 5, 2018

[Botany • 2018] Idimanthus amorphophalloides • A New Aroid Genus (Araceae-Caladieae) from Rio de Janeiro State, Brazil


 Idimanthus amorphophalloides E.G. Gonç.

in Gonçalves, 2018

Abstract

The monotypic genus Idimanthus (Araceae-Caladieae), represented by the species Idimanthus amorphophalloides, is here described and illustrated. It differs from all Caladieae by its connective ending in a rostrate beak turned downward, but the combination of cormous geophytic stem, copious endosperm, densely arranged fertile flowers and sterile flowers densely arranged in an apical appendix did not match any other genera in the tribe. It was collected in a marble outcrop in Northern Rio de Janeiro state, in the county of Italva, nearby the city of Cardoso Moreira as an understory herb. The aspect of leafless inflorescences with a long apical staminoidal area appearing directly from the soil is remarkably peculiar for Southeastern Brazilian aroids.

Keywords: Atlantic forest, geophyte, rocky outcrop, Monocots


Figure 2. Idimanthus amorphophalloides. leafy specimens covering the ground in the habitat.


Idimanthus E.G.Gonç. gen. nov.

Eponymy:–– The generic name honors Idimá Gonçalves da Costa, an active plant collector from Rio de Janeiro, which spotted this plant in the wild for the first time and cultivated it.

 Idimanthus amorphophalloides E.G. Gonç., sp. nov.

Etymology:— The specific epithet aludes the resemblance with a miniature specimen of the aroid genus Amorphophallus, mainly because of its peculiar habit of flowering much before any sight of the leaves.


Eduardo G. Gonçalves. 2018. Idimanthus: A New Aroid Genus (Araceae—Caladieae) from Rio de Janeiro State, Brasil. Phytotaxa.  351(1); 88–92. DOI:  10.11646/hytotaxa.351.1.8