Alatococcus, a new genus of Sapindaceae from Espirito Santo, Brazil

Abstract

The new genus Alatococcus (Sapindaceae) is described from Espirito Santo, Brazil. Alatococcus seems to be closely related to Scyphonychium of northeastern Brazil, as they both share similar vegetative morphology, flowers with zygomorphic calyx, fruits with indehiscent mericarps, and isopolar, tricolporate pollen grains. They however differ by the shape of the nectary disc, petal appendages, mericarps, and pollen shape and ornamentation. The new species Alatococcus siqueirae is described and illustrated.

Keywords: Alatococcus; Brazil; Espirito Santo; Sapindaceae; Scyphonychium.

Figure 1.

Alatococcus siqueirae A Branch with detail of petiolules B Sub-cincinnus C Staminate flower bud D Staminate flower E Petal with appendage, adaxial and lateral views F Portion of staminate flower showing unilateral nectary disc and stamens, staminate flower with removed petal showing nectary disc, stamens and pistillode G Pistillode, top and lateral views H Fruit, two lateral views I Dissected fruit showing wing, locule, mesocarp and seed, seed basal view. A, H–I from Folli 1761 (K); B–G from Siqueira and Magnago 639 (US).

Figure 2.

Pollen of Alatococcus siqueirae. A Equatorial view showing colpus and pore B Polar view showing three colpi and striate ornamentation. All from Siqueira & Magnago 639 (US).