Cuneate shadowpalm

The Essence

"Geonoma cuneata is a small, shade-tolerant understorey palm whose native range runs from south-eastern Nicaragua through Central America and western Colombia to western Ecuador and north-western Venezuela. The account of the species in Henderson's revision of Geonoma, reproduced by Palmweb, calls it the fourth most variable species in the genus, and Plants of the World Online accepts nine subspecies. Its flowering biology has been studied in unusual detail. Borchsenius (1997) found that var. sodiroi flowers from December to April with a February peak, each inflorescence in anthesis for only six to eight days and with non-overlapping male and female phases; the flowers open at dawn and are pollinated by drosophilid and sphaerocerid flies, unlike the sympatric G. irena, which flowers year-round and is pollinated by meliponid and halictid bees. The paper concludes that these differences in reproductive biology act as an important barrier to gene flow between the two co-occurring taxa. At La Selva in Costa Rica the species is a preferred host plant of the forest grasshopper Microtylopteryx hebardi: of three palms studied, its leaves had the highest percentage water content, the highest fresh and dry mass per unit leaf area and the lowest percentage crude lignin, and herbivory attributable to it was greatest in the light gaps where the grasshopper was most abundant. Several peoples use the palm. The Awa of Ecuador and Colombia thatch roofs with the whole leaves and use leaves and stems medicinally and in veterinary practice, and record the fruits and stems as wildlife attractants; the Cayapa eat the fruits; and the Tsachila mash the leaves in water together with cloth to dye textiles black. It is assessed as Least Concern by the IUCN, with a stable population trend, and remains rather rare in cultivation."

The name was published by Spruce in J. Linn. Soc., Bot. 11: 104 (1869), crediting an earlier name of Hermann Wendland, hence the author string H.Wendl. ex Spruce. Borchsenius (1999) studied variation within the species in western Ecuador using morphometric methods, and concluded that the varietal classification of Henderson et al. (1995) was not applicable there, much less across the whole range of the species. Henderson's revision of the genus (A revision of Geonoma (Arecaceae), Phytotaxa 17: 1-271, 2011) instead divided it into subspecies, and POWO accepts nine: subsp. cuneata, guanacastensis, indivisa, irena, linearis, minor, procumbens, rubra and sodiroi. The same account places the species in the G. cuneata clade with G. brenesii, G. epetiolata, G. hugonis and G. monospatha, from which it differs in its crenulate or shallowly lobed staminodial tubes.