adaxially

Leaves 15-20 in number, coriaceous, forming a broad crateriform rosette; sheaths oblong-elliptic, 34-45 x 19-21 cm, dark castaneous and densely brown-lepidote on both sides; blades sublinear, suberectarcuate at anthesis, slightly if at all narrowed at base, 180-200 x 16-17 cm, green, nerved mainly at apex, abaxially densely and minutely white-lepidote, adaxially subdensely and inconspicuously white-lepidote, apex acuminate, ending in a dark, pungent spine, ca.

Leaves opposite, rarely whorled or alternate, sometimes with domatia abaxially in axils of secondary veins with midvein and/or cluster of colleters adaxially at juncture of apex of petiole and base of blade.

Vernation: 0 = erect; 1 = adaxially rolled crosiers; 2 = abaxially rolled crosiers; 3 = erect rachis, abaxially rolled crosiers on primary pinnae, and adaxially rolled crosiers on more distal frond segments.

Leaves monomorphic, 16-32 x 6-12 cm; stipes 50-60% the length of the fronds, atropurpureous to ebeneous, mainly glabrous, with scattered scales near the base, shining to weakly glaucous; stipe scales narrowly triangular, stramineous proximally, castaneous distally, margins with spreading to recurved teeth; blades oblong to broadly obovate, pinnate (entire when young), glabrous, pinna bases overlapping the rachis; rachises atropurpureous to ebeneus, abaxially glabrous, adaxially with minute scattered hairs 0.

2 cm thick toward the apex, green toward the base, reddish toward the apex, opaque, densely white-lepidote abaxially, trichomes not obscuring the color of the blades, adaxially sparsely and inconspicuously white-lepidote to glabrescent, nerved adaxially, apex long acuminate-caudate, pungent, margins white-lepidote to glabrous, subdensely spinose, spines 1-1.

50 cm tall; dark brown to blackish petioles and rachises, the rachises not flexuous, bearing hairs and filiform scales, adaxially slightly sulcate and with two narrow wings; the laminae light green, 2-3-pinnate at the base, sometimes the proximal pinnules only lobate, subcoriaceous and glabrous on the laminar tissue; pinnules varying from ovate to lanceolate (Figs.

Leaves to 80 cm long, deciduous along a straight line in about 70-90 mm from the leaf base, the apex of the remaining rest incurving; sheaths to 50 mm wide, to 25 mm high, abaxially brown-castaneous, adaxially light brown, entire; blades grass-like, 7-17 mm wide, linear, long attenuate, entire, strongly canaled at the base, adaxial glabrous and abaxail pubescent of simple hears.

Lamina large, 130-202 x 40-65 cm, pinnate-pinnatisect, elliptic to lanceolate, dark green adaxially, pale green abaxially, with a pinnatifid apex, subcoriaceous to coriaceous, rachis dark brown and shiny, glabrous adaxially, few lower pinnae at the base, abruptly narrowed and more sparsely placed.

5 cm, strongly coriaceous, green, inconspicously and sparsely white-lepidote adaxially but appearing glabrous, abaxially glabrous, suberect, apex acute and apiculate to abruptly acuminate to shortly caudate, slightly recurved.

Subula semiterete, adaxially flat, abaxially convex.

2 cm wide, ovate, gradually merging into the blade, adaxially densely covered with brown-centered trichomes, abaxially with silvery subpruinose trichomes; blades to 10 cm long, ca.

5 mm wide; pinnae 1-11 cm long, less than I cm wide, flabellate to linear-lanceate, subfalcate, 2-5 pairs, the bases cuneate, non-auriculate, apices obtuse to long-attenuate, margins dentate; veins mostly simple except for the proximal ones, which are forked, readily visible on both sides, vein ends expanded adaxially.

8 cm wide at the base, 2-5 mm thick near the base, strongly coriaceous, subspreading-arcuate, distinctly channeled mainly toward the base, dark red, abaxially conspicuously nerved and densely adpressed and coarsely whitelepidote, trichomes concentrated along the intercostal zone and not at all obscuring the blade color, adaxially glabrous, margins erect to suberect, densely spinose at the base to laxly spinose toward the apex, spines narrowly-triangular, acicular, spreading (basal ones) to antrorse-uncinate (the apical ones), castaneous toward the apex, glabrous, 2-3 mm long, 1-1.

Megaiastrum differs from other dryopteroid genera by lamina cutting, venation, and type of hairs on the axes adaxially.

Leaves rosulate, spreading, 15 to 25 in number, 30-75 cm long; sheaths elliptic, 8-20 x 4-10 cm, moderately coriaceous, usually paler than the blades, somewhat reddish striate, appressed dark punctatelepidote, more so adaxially; blades ligulate, broadly acute to accuminate, 3-6 cm wide, coriaceous, nerved, scattered punctate-lepidote throughout, abaxially dark purple-red, adaxially dark green.