Alsophila grevilleana (Mart.) D. S. Conant

Cyathea elegans Hew. Mag. Nat. Hist. II. 2 : 466. 1838
Cyathea arb or ea pallida Hook. Sp. Fil. 1 : 17. 1844.
Caudex erect, 3-7 meters high, 5-10 cm. in diameter, densely covered (especially in smaller plants) with old stipe-bases, the eventual scars rough with projecting fibrovascular bundles; stipe 10-30 cm. long, 2 cm. in diameter at the base, dark-brown, minutely puberulofurfuraceous, bearing on the under surface a few deciduous subulate glossy darkbrown scales and armed with a few short long-pointed curved spines, and commonly bearing also a pair of abortive pinnae ; lamina ample, 2-3 meters long, 90-130 cm. broad, chartaceo-coriaceous, tripinnate, dark-green, the rachis pale-brown, puberulous, smooth or below somewhat muricate, the secondary rachises similar ; pinnae approximate, oblonglanceolate, 45-70 cm. long, 15-22 cm. broad, sessile or the lowermost short-stalked (1-1.5 cm.) ; pinnules 25-35 pairs, approximate, sessile, patent, 8-10 cm. long, 1.2-2 cm. broad, lanceolate-oblong, cut nearly or quite to the costa, the apex serrate-acuminate, the costa brownish, densely long-setose above, below sparingly furfuraceopaleaceous and pilose in the outer part with stiff yellowish hairs ; segments 18-20 pairs, subfalcate, oblong, slightly oblique, acute, the basal ones slightly apart and subsessile, the others approximate and adnate, the margins subrevolute, crenate-serrate, doubly so below; veins (7-10 pairs) onceor twice-forked, naked ; costulae naked above, below bearing a few yellowish-brown bullate scales and stiff yellowish hairs ; sori near the costule at the forking of the veins, 4-6 pairs, occupying two thirds or less of the segment; indusium very deeply cyathiform, or before maturity ovoid and greatly constricted at the mouth, membranous, pale-castaneous ; receptacle conical, dark-grayish, minutely f urf uraceous .
Type locality : Mayday Mountains, Jamaica.
BiSTRiBUTiON : Apparently confined to Jamaica, there common in forests at from 300 to 1200 meters elevation.

Alsophila grevilleana, synonym Cyathea grevilleana, is a species of tree fern endemic to Jamaica, where it grows in moist gullies and on wooded hills in both calcareous and noncalcareous soils at an altitude of 200–1200 m. The trunk of this plant is erect, about 7 m tall, and 10–15 cm in diameter. It is characteristically clothed in old stipe bases, brown scales and blackish spines. Fronds are tripinnate, dark green in colour, and up to 4 m in length. The last pinnae are sometimes separated, forming a distinctive clump around the trunk apex. The rachis is yellow-brown and almost smooth. This species has a long, dark brown stipe with a few scattered spines. Sori are produced in four to six pairs along the pinnule midvein. They are protected by pale brown indusia that are cup-like in appearance.

A. grevilleana forms part of the complex centered on Alsophila woodwardioides comprising six very similar taxa from the Greater Antilles. The other five species are Alsophila jimeneziana (syn. Cyathea crassa), Alsophila fulgens, Alsophila portoricensis and Alsophila tussacii. Large and Braggins (2004) note that this group is known to cross with members of the Alsophila minor complex.

The specific epithet grevilleana commemorates Robert Kaye Greville (1794-1866), who collected the type specimen in Jamaica in 1832.