Alsophila grevilleana

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. Cy......read more on Wikipedia.