Etymology: Based upon the occurrence of the type specimens being from Puerto Rico. Historical notes: After the description of Zamia portoricensis the species remained enigmatic and generally unrecognized for many years because of a paucity of collections. This is part due to its restricted and sporadic distribution. It is clear now that plants in the field and cultivation maintain their morphological characters. Distinguishing features: Z. portoricensis most closely resembles Z. angustifolia. It can be distinguished from Z. angustifolia by its longer leaves of up to 1.5 m long, by its wider (> 5 mm.), caniculate leaflets with acute apices, and by its reddish brown cones. In contrast, Z. angustifolia has leaves generally less than 1 m long, narrow leaflets (< 5 mm wide) blunt tipped leaflets that often appear rolled into a tube, and cones that are grayish to black. Z. portoricensis differs from Z. integrifolia in having entire leaflet margins whereas the leaflet margins of Z. integrifolia always have a few apical callous teeth. Distribution and habitat: One of the Caribbean species of Zamia that is found only in Western Puerto Rico where it grows on very dry limestone soils that often contain an element of serpentine. Conservation: Z. portoricensis has become very rare in Puerto Rico in part to development but also as a result over collection for nursery plants. Although in protected parks and a National Forest, this has done little to protect the species from collecting and plants can be found in plant stores in New York City labeled as Z. pumila and Z. floridana. However, the species is easily raised from seed and young plants have begun to appear on the market and artificial propagation appears to be in place. Of more concern is the lack of seed set in one of the larger populations. In visits to this population every year for the past seven years, neither seeds nor potential pollinating insect have been seen. Older pollen cones do not have the indicator weevil exit holes. Thus, it appears that the pollinator(s) may have been eradicated as a result of the aerial application of pesticides for local agriculture. 1997 IUCN Red List of Threatened Plants Category V,II,V.
Description:
Stem subterranean and tuberous, up to 15 cm. diam., often dichotomously branched. Cataphylls from 1-2 cm long, sheathing at first, with a pair of inconspicuous stipules. Leaves 2-10, 0.5-1.5 m long; petioles with stipules, smooth; rachis bearing 5-30 pairs of opposite to subopposite leaflets, smooth. Leaflets linear 8-25 cm long and 0.5-0.8 cm wide, often caniculate above, acute apically, entire. Pollen cones pedunculate, reddish brown, 1-10, cylindrical but gradually tapering towards acute apex, each 3-15 cm long and 0.8-2 cm in diameter, densely pubescent. Seed cones reddish brown, usually solitary but occasionally up to 3, cylindrical to slightly ovoid with blunt or slightly acute apex, each 6-12 cm long and 4-5 cm in diameter, densely pubescent. Seeds with a red to orange-red sarcotesta, ovoid, 1-2 cm long. 2n = 16.
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