Astrocaryum

Astrocaryum
 G. Mey.


Original
reference:
Prim. Fl. Esseq. 265 (1818)


Morphology:
Medium to very large, monoecious palms, armed with black or pale grey spines. Stems solitary or clustered. Leaves pinnate, regularly divided, often whitish green below. Inflorescences large, elongate, once branched. Flowers unisexual, arranged in a very characteristic way: the basal part of the lower branches bear a few widely spaced flower groups, each with one large female and two small male flowers, while the terminal part bears densely positioned solitary male flowers forming a finger-like structure. Male flowers with 3 free sepals and 3 free petals, 6 stamens, and a small pistillode; female flowers with sepals, petals, and staminodes each united in a truncate tube, and an ovary formed by 3 united carpels, with a head shaped stigma borne on a short style. Fruits medium sized to large, glabrous, tomentose, or covered with black bristles; endocarp bony, with three distal germination pores. Seedling leaves simple and bifid.



Distribution
and diversity: The number of species in the genus is disputed, with estimates for the Amazon ranging from 10 to 24 species. The genus occurs in dry and moist tropical and premontane forest from Central America to Brazil and Bolivia, usually below 1000 m elevation.

Notes:
Astrocaryum, together with Acrocomia, Gastrococos, Aiphanes, Bactris and Desmoncus, make up the subtribe Bactridinae, a group of spiny Neotropical palms with cocosoid fruits. Within that group, Astrocaryum is unique in its flower arrangement (see description above). The genus is divided into two natural subgenera: Monogynanthus, with one female flower borne at the base of each inflorescence branch and bristly fruits; and Pleiogynanthus, with several female flowers per inflorescence branch and non-bristly fruits.


Synonym
list
(3)

 

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