Zamia paucijuga Wieland
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Authority
Nicolalde-Morejón, Fernando, et al. 2009. Taxonomic revision of
in Mega-Mexico. Brittonia. 61 (4): 301-335. -
Family
Zamiaceae
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Scientific Name
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Description
Species Description - Stem hypogeous, branching dichotomously with age, 15-27 cm long, 8-13 cm in diam. Cataphylls coriaceous, persistent, base triangular, apex aristate, 4.5x3.4 cm at base, brown tomentose. Ptyxis inflexed. Leaves 2- 3, ascending to descending 41-95x29-36 cm wide, brownish when emerging; petiole 10.2- 32 cm long, green in young leaves, subterete, armed with prickles up to 4 mm long; rachis subterete, up to 56 cm long, with few prickles along the proximal third. Leaflets 5-28 pairs sessile, coriaceous, lanceolate, opposite to subopposite, apex acute, base attenuate, mar- gins serrulate to slightly dentate along distal third, subrevolute; articulations brownish in young leaflets, 0.4-0.6 cm wide; the median leaflets 14-19x2.3-3.4 cm. Pollen strobili usually 1-2, erect, cylindrical, 6.3-11 cm long, 2.1-2.6 cm in diam, light brown tomentulose, apex acute; peduncle light- brown tomentose, 6.3 cm long, 1.2 cm in diam; pollen sporangiophores cuneiform, dis- tal face hexagonal-truncate, 0.3 cm long, fertile abaxial surface with 6-8 bisporangiate synangia per lobe. Ovulate strobili usually solitary, erect, ellipsoid to cylindrical, 8.1 cm long, 5.2 cm in diam, brown-yellowish, tomentulose, apex apiculate; peduncle densely brown tomentose, 3.9 cm long, 1.3 cm in diam; megasporangiophores peltate, distal face hexagonal - truncate, 0.6 - 0.8 cm high, 1.1 -1.5 cm wide. Seeds ovoid, sarcotesta pink when immature, orange at maturity, 2 - 2.8 cm long, 1.5- 1.7 cm in diam, sclerotesta smooth. Chromosome number. - 2n=23, 34, 25, 26, 27, 28 (Moretti & Sabato, 1984).
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Discussion
Etymology. - The specific epithet alludes to few leaflet pairs per leaf.
Distinguishing features - Zamia paucijuga is highly variable morphologically and in chromosome number and karyotype (Moretti, 1990a, b). This may represent more than one entity under the concept of Z paucijuga sensu stricto Wieland (1916). This species shares a number of characteristics with Z loddigesii, being small plants with under- ground contractile stems and having coriaceous leaflets with marginal teeth. Nevertheless, it differs from Z loddigesii in having highly coriaceous leaflets with longer marginal teeth, and seeds with an orange sarcotesta at maturity as contrasted to the red sarcotesta of Z paucijuga. Zamia paucijuga occurs along the Pacific seaboard of Mexico whereas Z loddi- gesii is known generally from the Gulf of Mexico seaboard.