Etymology: Named for George Skinner a plant collector who worked mainly in Central America. Historical notes: Zamia skinneri would appear to part of a complex composed of Z. dressleri in Panama; Z. neurophyllidia in Panama, Costa Rica, and Nicaragua; Z. amplifolia and Z. roezlii Linden in the Choco of Colombia and adjacent Ecuador; and Z. wallisii in Northern Antioquia, Colombia. This grouping is based upon the common occurrence of the plicate appearance of the leaflets of these species. This character and simultaneous rather than sequential leaf production, prompted Regel (1876) to erect the segregate genus Aulacophyllum. However, no other synapomorphies have been found to support Aulacophyllum as a genus (Sabato, 1990). Moreover, the distinction between simultaneous and sequential leaf production in Zamia seems problematic at best. Distinguishing features: Zamia skinneri is the largest Central American Zamia and is unmistakable with its massive trunk, leaves, and strobili. It is closest in overall morphology to Z. neurophyllidia. Zamia skinneri has very large leaves with 4-8 (10) pairs of large leaflets that are from 12-18 cm wide and 30-50 cm long. In contrast, Z. neurophyllidia has smaller leaves with up to 12 pairs of leaflets that are 5-10 cm wide and 20-35 cm long. Generally the leaflet margins of Z. neurophyllidia have from 10-12 prominent teeth along the margin whereas the leaflet margins of Z. skinneri have diminutive teeth located in the upper third of the margin. Distribution and habitat: Zamia skinneri occurs in primary rainforest from northern to central Atlantic Panama at elevations from 50-750 m. It grows as an understory plant in primary rainforest to the lower limits of cloud forest. Conservation: 1997 IUCN Red List of Threatened Plants Category R,II,V.
Description:
Stem arborescent, to 2.5 m tall. Leaves 3-6, 1-2 m long; petiole 0.5-1 m long, sparsely to densely prickled; rachis with 6-8 (10) pairs of leaflets, occasionally with a few prickles in the lower third. Leaflets elliptic, grooved between the veins on the adaxial surface, cuneate basally, acuminate apically, margins serrate in upper third, the median ones 30-50 cm long, 12-18 cm wide. Pollen cones cream to tan becoming reddish with age, cylindrical to elongate-cylindrical, 8-12 cm long, 1-2 cm diam. Seed cones brown, short pedunculate, cylindrical to ovoid cylindrical, 20-40 (50) cm long, 8-12 cm diam. Seeds red, ovoid, 1.5-2.5 cm diam. 2n = 22.
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