Blanchetiodendron Barneby & J.W.Grimes

VII. BLANCHETIODENDRON Barneby & Grimes

Blanchetiodendron Barneby & Grimes, gen. nov. monotypicum pro Enterolobium seu Pithecolobium blanchetii Bentham conditum, inter Leucochloron et Albiziam sect. Arthrosamaneam quasi intermedium, illius forsan propius: Leucochlori habet gemmas perulatas striatas, legumen plano-compressum necnon semina disciformia tenuitestata pleuro-grammate orbata, Albiziae autem inflorescentiam pseudoracemosum axillarem efoliatam vel terminalem paniculatam et flosculum terminalem heteromorphum, ideo ab utroque genere sejungendum. — Sp. unica: B. blanchetii (Bentham) Barneby & Grimes = Enterolobium blanchetii Bentham.

Description of this monotypic genus is implicit in that of its one species given below. Its diagnostic features, shared as it were between Leucochloron and Albizia sect. Arthrosamanea are: striate axillary perules; an efoliate inflorescence consisting of axillary pseudoracemes (simple or sometimes remotely branched) and often a small terminal panicle; flowers dimorphic, the peripheral ones of each unit pedicellate, the terminal ones sessile; pod broad-linear piano- compressed, the valves papery, dehiscent inertly through both sutures; seeds thinly disciform, the lustrous testa translucent, narrowly winged by a prominent peripheral nerve, exareolate. The perules, pod, and seed are characteristic of Leucochloron, but the organization of the inflorescence and the umbelliform capitula including an enlarged sessile terminal flower would be anomalous in that setting. On the other hand, the inflorescence and pod, except for the seed, are compatible with Albizia sect. Arthrosamanea, but the perulate resting-buds and the thin exareolate seed- coat would be inappropriate exceptions in that genus. In effect, Blanchetiodendron blanchetii is clearly related on the one hand to Leucochloron and Chloroleucon, and on the other to Albizia sect. Arthrosamanea, but morphologically isolated between these taxa. This ambiguous character is reflected in the taxonomic history. The species was first described, from flowering material, as an Enterolobium, and it was transferred to Pithecellobium when the fruit became known. Clearly not conspecific with Pithecellobium sens. str., it has recently been accommodated in Albizia sens. lat., but there also appears to us peripheral.