Acrostichum

Linnaeus

Sp. Pl. 2: 1067. 1753; Gen. Pl. ed. 5, 484, 1754.

Common names: Leather fern
Etymology: Greek acros, at the end, tip, and stichos, row, referring to the distal spore-bearing pinnae
Treatment appears in FNA Volume 2.

Plants terrestrial in fresh or saltwater habitats. Stems erect or creeping, branched; scales dark-brown, concolored, linear-lanceolate, margins entire. Leaves slightly dimorphic, clustered, 1–5 m. Petiole brown, with a single groove adaxially, glabrous, smooth or with scale scars, with several abaxial vascular-bundles and 2 adaxial vascular-bundles. Blade lanceolate, pinnate, leathery, abaxially glabrous or hispid, adaxially dull, not striate, glabrous; rachis straight. Pinnae stalked, free from rachis, narrowly oblong to lanceolate, 2–5 cm wide; base cuneate; stalk green; margins plane; fertile leaves bearing sporangia on most pinnae or on only more distal pinnae (fertile pinnae may slightly smaller than sterile ones). Veins of pinnae conspicuous, strongly anastomosing. False indusia absent. Sporangia spread over abaxial surface, mixed with paraphyses (sori acrostichoid), containing 64 spores. Spores yellow, tetrahedral, minutely tuberculate or roughened, equatorial flange absent. x = 30.

Distribution

Worldwide, warm and tropical regions

Discussion

Species 3, possibly more (2 in the flora).

Key

1 Fertile leaves with only most distal pinnae fertile; pinnae often distant and not overlapping; costal areoles usually narrow, 3 or more times longer than wide; paraphyses terminating in isodiametric, irregularly lobed cell. Acrostichum aureum
1 Fertile leaves with most pinnae fertile; pinnae distant to closely spaced and ± overlapping; costal areoles usually broad, less than 3 times longer than wide; paraphyses terminating in horizontally extended, smooth or lobed cell. Acrostichum danaeifolium
... more about "Acrostichum"
Robert M. Lloyd +
Linnaeus +
cuneate +
glabrous +  and hispid +
lanceolate +
Leather fern +
Worldwide +  and warm and tropical regions +
Greek acros, at the end, tip, and stichos, row, referring to the distal spore-bearing pinnae +
yellow +  and white +
obcordate;reniform +
monomorphic +
recurved +  and reflexed +
noncircinate +  and circinate +
100 cm1,000 mm <br />1 m <br /> (500 cm5,000 mm <br />5 m <br />) +
2 cm20 mm <br />0.02 m <br /> (5 cm50 mm <br />0.05 m <br />) +
adams1979b +, garcia1978a +, lloyd1980a +  and small1938a +
concolored;dark-brown +
persistent +
linear-lanceolate +
tetrahedral +
creeping +  and erect +
Acrostichum +
Pteridaceae +
1 +  and several +
crescent--shaped +  and roundish +
anastomosing +
conspicuous +