Ceratozamia huastecorum

Family: Cycadae    Cycadale

Nom commun: aucun connu

zone de rusticité: 9b     Voir les cartes des zones de rusticité pour le Royaume-Uni et les États-Unis

Identification:
Cycad with short non-branching trunk, subglobose, erect, semihypogeous, reddish brown armed with persistent petiole and cataphyll bases, 12-13 cm (mean=12.2) long, 11-13.5 cm (mean=12)diameter (N=4); leaf cataphylls triangular, lanose, stipulate, 3-3.2 cm long, 2.6-2.8 cm wide at base. LEAVES pinnate, glabrous, 3-5, ascending, extending forming an open apical crown, 50-73 cm (mean=60) long, 30-42 cm (mean=38) wide (N=25); petiole and rachis terete, armed with few prickles that diminish in number and thickness from proximal to distal ends; petiole linear, 19-41 cm (mean=25) long, 0.8 cm diameter, tomentose at base, rachis 30-64 cm (mean=57) long; LEAFLETS coriaceous, 5-16 (mean=15) pairs, opposite to subopposite at times subalternate along proximal and mid portion of leaf, oblanceolate, rarely bidentate at or near asymmetrical apex, apex acuminate, margin entire, subrevolute, brilliant green on adaxial surface, light green on abaxial, 6.5-21 cm (mean=16.5) long, 3.2-6.5 cm (mean=4) wide, veins visible 30-38 (mean=32), intervein distance 1.1-1.6 mm (mean=1.4) (allN=25). MICROSTROBILI erect, cylindrical tapering towards apex, pale to light green, 16 cm long 3 cm diameter at maturity, peduncle scarcely tomentose 3-21 cm (mean=8) long (N=5); microsporophylls indefinite, cuneiform, spirally arranged along axis forming apparent vertical rows, bicornate at distal face, fertile portion covering c. two thirds of the proximal abaxial surface, 8-10 mm (mean=9.2) long, 7.2-9.8 mm (mean=8.6) wide (N=20), distal horns 1.1-1.2 mm long, distance between horns 5-6.8 mm (mean=6), microsporangia indefinite, in sori of three, 0.9-1.1 mm long, c. 0.9 mm wide, longitudinally dehiscent. MEGASTROBILI cylindrical to barrel-shaped, erect, olive green, 13.5 cm long, 5 cm diameter, peduncle 3-8 cm long; megasporophylls indefinite, peltate, 1.8-2 cm long, 1.4-1.8 cm (mean=1.6) wide, distal face hexagonal, bicornate, indument scarce, grisaceous, horns 4-6.2 mm (mean=4.5) long, distance between horns 1.3-1.8 (mean=1.5) cm. SEEDS ovate, 1.2 cm long, 0.9-1 cm wide, sarcotesta brown at maturity, sclerotesta beige, smooth. Chromosome number 2n=16.

Informations générales:
This cycad is found in an area of cloud forest in northern Veracruz. It inhabits Oak forest understorey at elevations from 900 to 1300 m. Populations are found under partial shade in inaccessible sites along the mountain crest, on basalt rocky substrate. They occur on a stony, medium texture lithosol and luvisol substrate rich in humus. Winds charged with moisture lash these sites with great strength and mists are frequent.

Distribution:

Originaire de, Mexico


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