antrorse

In approximately 25% of the male specimens examined, branched rays with small conical or slightly antrorse hooks on the ventral surface of ray.

Leaves 4-9; blades 4-23 cm long, (1-)1.4-3.9 mm wide, flattish or channelled (at least proximally), glabrous, margins nearly smooth or with unbranched and 2-branched prickle hairs, the unbranched ones antrorse or retrorse; inner band of leaf sheaths white-hyaline or pale brown, glabrous, the apex slightly concave; ligules 0.5-1.5 mm long, rounded.

In this study, small seed size, antrorse hairs, hygroscopic awns, pappuses, and mucilaginous seed coats appeared to result in higher entrapment over the range of particle sizes.

Teeth in about 5 rows; 7-8 plus one emerging tooth along middle, 29 along posterior margin; compressed, along margins and anteriorly slender, unicuspid; mediad and caudad slightly coarser and longer, bicuspid, with strong posterior, antrorse cusp and minor anterior blunt cusp subdistally.

2 mm thick near the base, green throughout before anthesis and rose at base at anthesis, opaque, abaxially densely and coarsely white-lepidote with trichomes slightly obscuring leaf color, adaxially subdensely to sparsely and inconspicuously white-lepidote, margins densely to sparsely spinulose, spines subtriangular-uncinate, antrorse, yellowish, 0.5-1 mm long, 2-7 mm apart.

2.5 cm long, 4.5-5 cm in diameter (including floral bracts), floral bracts narrowly ovate, apex acuminate, distinctly canaliculate, navicular, ecarinate, strongly recurved, exceeding the sepals, yellowish-green to orange (when fully exposed), thin in texture, inconspicuously and sparsely white-lepidote near the base to glabrous, glabrous toward the apex, nerved abaxially, 25-35 x 11-15 mm, densely spinose, spines narrowly triangular, the basal ones retrorse the median to apical ones antrorse, uncinate, greenish except for the pale castaneous apex, 0.5-1.5 mm long, 0.5-1 mm apart.