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FOC | Family List | FOC Vol. 2-3 | Dennstaedtiaceae

2. Pteridium Gleditsch ex Scopoli, Fl. Carniol. 169. 1760.

蕨属 jue shu

Authors: Wenbo Liao, Ding Mingyan, Zhaohong Wu & Jefferson Prado

Filix Ludwig (1757), not Séguier (1754), nor Adanson (1763).

Plants terrestrial, robust. Rhizome brownish black, thick, ca. 5 mm in diam., hypogeal, densely clothed with rusty yellow to castaneous hairs, without scales. Fronds 50-130 cm; stipe with several vascular bundles; lamina large, often ovate or ovate-triangular, subleathery to papery, abaxially ± pilose, adaxially glabrous or sparsely hairy, 3- or 4-pinnate-pinnatifid; costae of ultimate pinnae clothed with fine gray-brown hairs, rarely glabrescent; rachises grooved adaxially, glabrous or pubescent; pinnae subopposite or alternate, stalked, basal pinnae pair larger than other pinnae, triangular; venation of ultimate pinnae pinnate, veins 2-forked, adaxially conspicuously prominent. Sori submarginal, linear, paraphyses not present; indusia formed by two layers; outer layer consisting of thin reflexed margin of lamina, persistent; inner layer thinner, vestigial, not conspicuous, sometimes nearly degenerate; sporangia long stalked; spores trilete, with low nipple-shaped protuberances. x = 13.

About 13 species: widely distributed worldwide, but mainly in the tropics; six species (three endemic) in China.

1 Rachises and costae glabrous in adaxial grooves   (2)
+ Rachises and costae densely hairy in adaxial grooves (at least when young)   (4)
2 (1) Ultimate segments broadly lanceolate to oblong, not wider than their own width apart.   1 P. aquilinum
+ Ultimate segments linear, often 1-2 ?their own width apart   (3)
3 (2) Fronds leathery when dried; ultimate segments linear, ca. 2.5 mm wide, abaxially veins hairy.   2 P. esculentum
+ Fronds papery when dried; ultimate segments broadly linear-falcate, 3-4 mm wide, abaxially subglabrous except on midvein.   3 P. falcatum
4 (1) Fronds subleathery; pinnules lanceolate, up to 8 ?1.5 cm.   4 P. revolutum
+ Fronds papery or herbaceous; pinnules narrowly linear or linear-lanceolate, 13-20 ?ca. 3 cm   (5)
5 (4) Fronds papery; pinnules narrowly linear, up to ca. 20 cm, adaxially ?glabrous.   5 P. lineare
+ Fronds herbaceous; pinnules linear-lanceolate, ca. 13 cm, adaxially pilose.   6 P. yunnanense

Lower Taxa


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