Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.
1 Pistillate spikes all from the base of the plant |
1 Pistillate spikes all or in part borne on the elongate, aboveground stem. |
..2 Bracts of the lowermost non-basal spike with well-developed sheath > 4 mm long. |
....3 Beak of perigynium with distinct teeth > 0.6 mm long |
....3 Beak of perigynium entire, notched, or with indistinct teeth < 0.6 mm long. |
......4 Bracts of the lowermost non-basal spike bladeless, or with a blade < 2 mm long. |
........5 Perigynia 2.0-2.9 mm long; leaf blades 0.9-3.3 mm wide |
........5 Perigynia 4-5 mm long; leaf blades 4-8 mm wide |
......4 Bracts of the lowermost non-basal spike with blade > 3 mm long (and often much longer). |
..........6 Achene tip with persistent, enlarged, circular style base |
..........6 Achene tip with at most a short apiculus. |
............ 7 Leaves pubescent or pilose |
............ 7 Leaves usually glabrous, to scabrous on the veins. |
............ ..8 Bases of plants brown |
............ ..8 Bases of plants distinctly red or purple. |
............ ....9 Lowermost pistillate scales awned; leaves somewhat septate-nodulose; plants usually long-rhizomatous and forming large clonal colonies |
............ ....9 Lowermost pistillate scales obtuse to acuminate; leaves not septate-nodulose; plants cespitose, short-rhizomatous |
..2 Bracts of the lowermost non-basal spike sheathless or with sheath < 4 mm long. |
............ ......10 Perigynia > 10 mm long. |
............ ........11 Pistillate spikes globose, about as long as wide; staminate spikes usually 1 |
............ ........11 Pistillate spikes cylindric, much longer than wide; staminate spikes 1-8 |
............ ......10 Perigynia < 10 mm long. |
............ ..........12 Perigynium beak with 2 teeth > 0.6 mm long |
............ ..........12 Perigynium beak entire or with teeth < 0.6 mm long. |
............ ............ 13 Terminal spike gynecandrous or pistillate |
............ ............ ..14 Perigynia papillate |
............ ............ ..14 Perigynia glabrous or pubescent. |
............ ............ ....15 Sheaths and blades both glabrous |
............ ............ ....15 Sheaths and/or blades pubescent |
............ ............ 13 Terminal spike staminate (or rarely androgynous). |
............ ............ ......16 Leaf sheaths (and usually the blades as well) pubescent. |
............ ............ ........17 Pistillate scales sometimes pubescent; pistillate spikes with 40-200 perigynia |
............ ............ ........17 Pistillate scales glabrous; pistillate spikes with < 40 (-50) perigynia. |
............ ............ ..........18 Perigynia usually < 3.2 mm long, the apex rounded and beakless, or abruptly beaked |
............ ............ ..........18 Perigynia > 3.5 mm long, the tip tapering or abruptly beaked. |
............ ............ ............ 19 Longer peduncles of pistillate spikes > 1 cm long; perigynia > 3× as long as wide, tapering gradually to the base |
............ ............ ............ 19 Longer peduncles of pistillate spikes 0-1 cm long; perigynia < 3× as long as wide, abruptly contracted to a short stipe at the base. |
............ ............ ............ ..20 Perigynia distinctly 20-30-veined; beak < 0.5 mm long |
............ ............ ............ ..20 Perigynia veinless except for 2 marginal veins; beak > 0.7 mm long |
............ ............ ......16 Leaf sheaths and blades glabrous to scabrous. |
............ ............ ............ ....21 Achene tip with persistent, enlarged, circular style base |
............ ............ ............ ....21 Achene tip with at most a short apiculus. |
............ ............ ............ ......22 Leaf blades scabrous on the upper surface; beak of perigynium recurved |
............ ............ ............ ......22 Leaf blades glabrous on the upper surface, often with rough margins or tip; beak of perigynium straight. |
............ ............ ............ ........23 Fronts of sheaths of lower leaves ladder-fibrillose; leaves and sheaths septate-nodulose (sometimes obscurely so) |
............ ............ ............ ........23 Fronts of leaf sheaths not ladder-fibrillose, sometimes breaking into longitudinal fibers; leaves and sheaths not septate-nodulose. |
............ ............ ............ ..........24 Perigynia strongly 12-30-veined. |
............ ............ ............ ............ 25 Pistillate scales with 3-7 (-10) veins |
............ ............ ............ ............ 25 Pistillate scales with 1-3 veins. |
............ ............ ............ ............ ..26 Leaf blades, at least toward the tip, M-shaped in cross-section when young, the upper surface usually with 2 marginal veins more prominent than the midvein; staminate spikes 1-4 |
............ ............ ............ ............ ..26 Leaf blades V-shaped in cross-section when young, the upper surface lacking 2 marginal veins more prominent than the midrib; staminate spike 1 |
............ ............ ............ ..........24 Perigynia 0-12-veined. |
............ ............ ............ ............ ....27 Proximal pistillate spike pendulous, perigynia usually > 30 per spike; terminal staminate spikes 1-3; [exotic] |
............ ............ ............ ............ ....27 Proximal pistillate spike erect, perigynia < 25 per spike; terminal staminate spikes 1; [native]. |
............ ............ ............ ............ ......28 Plants with at least some pistillate spikes basal; culms much shorter than the leaves |
............ ............ ............ ............ ......28 Plants with most pistillate spikes on obvious elongated stems; culms shorter than or longer than the leaves. |
............ ............ ............ ............ ........29 Upper leaves with blades > 2 cm long, longer than the sheaths |
............ ............ ............ ............ ........29 Upper leaves bladeless or with blades < 1 cm long and also shorter than the sheaths |
1 Apex of perigynium beak with 2 teeth at least (0.4-) 0.5 mm long. |
..2 Perigynia with 2 distinct marginal veins, otherwise veinless or only very faintly veined; leaves not septate-nodulose |
..2 Perigynia with 5+ distinct veins; at least proximal leaves septate-nodulose, rarely not. |
....3 Perigynia with serrulate wing on margins; spikes usually 20+, sessile, pistillate or androgynous and similar in appearance, forming a dense, ovoid or oblong head, rarely with proximal spike separated |
....3 Perigynia without wing on margins; spikes not more than 10, usually at least proximal shortly pedunculate, sometimes subsessile, distal and proximal spikes usually dissimilar in appearance, usually not crowded into a dense head. |
......4 Pistillate scales obtuse to acuminate, awnless or at most with a rough apiculus. |
........5 Staminate spike usually 1; perigynia 15-20-veined, each 10-20 mm long |
........5 Staminate spikes usually 1-3+; perigynia 6-15 (-22)-veined, each 4-10 (-12.5) mm. |
..........6 Perigynia 6-14 (-15)-veined |
..........6 Perigynia 14-25-veined |
............ 7 Perigynia narrowly ovate to subglobose, 2-2.5× as long as wide |
............ 7 Perigynia elliptic to ovate, 3-4.5× as long as wide |
......4 Pistillate scales, at least some, with a scabrous awn. |
............ ..8 Perigynia (9-) 10+ mm long. |
............ ....9 Pistillate spikes cylindric, much longer than wide; staminate spikes (1-) 2-6 |
............ ....9 Pistillate spikes globose, ovoid, or cylindric, about as long as wide; staminate spikes usually 1 |
............ ..8 Perigynia < 9 mm long. |
............ ......10 Upper pistillate scales with awn > ½ as long as the body |
............ ......10 Upper pistillate scales acute to short-awned, awn < ½ as long as the body. |
............ ........11 Beak of perigynia with teeth 1.1-3 mm long |
............ ........11 Beak of perigynia with teeth often < 1 mm long. |
............ ..........12 Staminate spikes 1 (-4); perigynium beak > 1.7 mm long |
............ ..........12 Staminate spikes 1-6; perigynium beak often < 1.7 mm long. |
............ ............ 13 Perigynia veined only at base; widest leaves < 4 mm wide |
............ ............ 13 Perigynium veined to tip of body and often into beak; widest leaves mostly > 4 mm wide. |
............ ............ ..14 Pistillate scales with margins serrulate distally; awn, when present, rough. |
............ ............ ....15 Perigynia 3.1-4.8 × 0.9-1.5 (-1.8) mm; staminate spikes 1-2 |
............ ............ ....15 Perigynia 2.5-8 × 1.2-3.5 mm; staminate spikes usually 3-7 |
............ ............ ..14 Pistillate scales with margins entire; awn, when present, usually smooth. |
............ ............ ......16 Perigynia 9-15-veined |
............ ............ ......16 Perigynia 14-25-veined. |
............ ............ ........17 Perigynia narrowly ovate to subglobose, 2-2.5× as long as wide |
............ ............ ........17 Perigynia elliptic to ovate, 3-4.5× as long as wide |
1 Apex of perigynium beak entire, emarginate, or with 2 teeth < 0.5 mm long. |
............ ............ ..........18 Perigynia minutely papillose, at least distally (at 20× magnification). |
............ ............ ............ 19 Some roots with yellow-brown felty covering |
............ ............ ............ 19 Roots brown or black, without yellow-brown felty covering, rarely with white felty covering. |
............ ............ ............ ..20 Leaf blades and/or sheaths pubescent, at least at junction of blade and sheath |
............ ............ ............ ..20 Leaf blades and sheaths glabrous. |
............ ............ ............ ....21 Terminal spike gynecandrous |
............ ............ ............ ....21 Terminal spike staminate or androgynous. |
............ ............ ............ ......22 Pistillate scales obtuse to acuminate or with awn < 1 mm long; staminate scales not awned |
............ ............ ............ ......22 Lower pistillate scales with awn 1.2-3.5 mm long; staminate scales awned |
............ ............ ..........18 Perigynia not papillose, essentially smooth. |
............ ............ ............ ........23 Terminal spike gynecandrous. |
............ ............ ............ ..........24 Perigynia with distinct beak 0.5-4 mm long. |
............ ............ ............ ............ 25 Larger spikes usually with > 50 perigynia; achenes 2-3 mm long |
............ ............ ............ ............ 25 Larger spikes with < 40 perigynia; achenes 1-2 mm long |
............ ............ ............ ..........24 Perigynia beakless or with beak < 0.5 mm long. |
............ ............ ............ ............ ..26 Adaxial side of leaves with 2 marginal veins more prominent than midvein; young leaves M-shaped in cross section. |
............ ............ ............ ............ ....27 Perigynia ovoid, usually > 1.5× as long as wide; apex tapered to beak; sheaths of proximal leaves not septate-nodulose |
............ ............ ............ ............ ....27 Perigynia subcircular, < 1.2× as long as wide; apex rounded, abruptly beaked; sheaths of proximal leaves septate-nodulose |
............ ............ ............ ............ ..26 Adaxial side of leaves without 2 marginal veins more prominent than midvein; young leaves V-shaped or rounded in cross section. |
............ ............ ............ ............ ......28 Leaf blades and/or sheaths pubescent, at least at junction of blade and sheath |
............ ............ ............ ............ ......28 Leaf blades and sheaths glabrous. |
............ ............ ............ ............ ........29 Perigynia erect or ascending |
............ ............ ............ ............ ........29 Perigynia ascending, spreading at about right angles, or reflexed when mature |
............ ............ ............ ........23 Terminal spike staminate or androgynous. |
............ ............ ............ ............ ..........30 Leaves and/or sheaths pubescent, at least at junction of blade and sheath. |
............ ............ ............ ............ ............ 31 Larger leaves 8-23 mm wide, only the sheaths pubescent |
............ ............ ............ ............ ............ 31 Leaves < 8 mm wide, blades and usually also the sheaths pubescent. |
............ ............ ............ ............ ............ ..32 Perigynium beak 0.5-3 mm long, often > 1 mm long, about 1/2 the length of the body; proximal pistillate scales awned |
............ ............ ............ ............ ............ ..32 Perigynium beak absent or not more than 0.5 (-0.7) mm long, not > 1/4 the length of the body; proximal pistillate scales acute, acuminate or cuspidate. |
............ ............ ............ ............ ..........30 Leaves and sheaths usually glabrous, rarely papillose. |
............ ............ ............ ............ ............ ....33 Style persistent on achene in fruit; larger leaves and sheaths usually at least sparsely septate-nodulose, rarely not. |
............ ............ ............ ............ ............ ......34 Perigynia (9-) 10+ mm long; staminate spike usually 1 |
............ ............ ............ ............ ............ ......34 Perigynia < 10 mm long; staminate spikes 1-5 (-7). |
............ ............ ............ ............ ............ ........35 Pistillate scales with margins serrulate distally, apex usually rough-awned. |
............ ............ ............ ............ ............ ..........36 Distal pistillate scales with apex acute to short-awned, awn < 1/2 as long as the body |
............ ............ ............ ............ ............ ..........36 Distal pistillate scales with apex long-awned, awn > 1/2 as long as the body |
............ ............ ............ ............ ............ ........35 Pistillate scales with margins entire, apex awnless or with short, smooth awn. |
............ ............ ............ ............ ............ ............ 37 Perigynia not inflated, thick walled, brownish, dull |
............ ............ ............ ............ ............ ............ 37 Perigynia slightly to strongly inflated, thin walled, yellowish to purplish, shiny |
............ ............ ............ ............ ............ ....33 Style deciduous; larger leaves and sheaths sometimes septate-nodulose, more often not. |
............ ............ ............ ............ ............ ............ ..38 Leaf blades, at least widest, M-shaped in cross section when young, adaxial surface with 2 marginal veins more prominent than midvein. |
............ ............ ............ ............ ............ ............ ....39 Widest leaf blades 8-23 mm wide, septate-nodulose |
............ ............ ............ ............ ............ ............ ....39 Widest leaf blades < 6 mm wide, not septate-nodulose. |
............ ............ ............ ............ ............ ............ ......40 Pistillate scales awned, longest awn > 0.5 mm long |
............ ............ ............ ............ ............ ............ ......40 Pistillate scales obtuse to acuminate or short-awned, awn < 0.2 mm long |
............ ............ ............ ............ ............ ............ ..38 Leaf blades V-shaped in cross section when young, adaxial surface without 2 marginal veins more prominent than midvein. |
............ ............ ............ ............ ............ ............ ........41 Proximal perigynia in each spike spreading at right angles or reflexed at maturity; leaf blades and sheaths sparsely septate-nodulose |
............ ............ ............ ............ ............ ............ ........41 Proximal perigynia in each spike ascending or spreading-ascending; leaf blades and sheaths not septate-nodulose. |
............ ............ ............ ............ ............ ............ ..........42 Plant base brown or blackish, without trace of red or purple |
............ ............ ............ ............ ............ ............ ..........42 Plant base red or purple tinged, sometimes only sparsely so. |
............ ............ ............ ............ ............ ............ ............ 43 Perigynia distinctly veined on faces; pistillate scales brown or black |
............ ............ ............ ............ ............ ............ ............ 43 Perigynia veinless or with veins only proximally; pistillate scales white-hyaline or red-brown |
1 Apex of perigynium beak terminated by 2 teeth, mostly > 0.5 mm long. |
..2 Perigynia > 4× as long as wide (8-15 × 1-3 mm). |
....3 Apical teeth of perigynium beak erect; achenes oblong-obovoid or obovoid; at least proximal pistillate scales with 3-5 (-7)-veined center |
....3 Apical teeth of perigynium beak reflexed; achenes elongate; pistillate scales with 1-veined center |
..2 Perigynia < 4× as long as wide. |
......4 Perigynia > (9-) 10 mm long. |
........5 Sheaths, at least the proximal sheath fronts, densely tomentose at mouth; apical teeth of perigynium beak often > 1 mm long |
........5 Sheaths glabrous; apical teeth of perigynium beak not more than 1 mm. |
..........6 Perigynia 7-11-, 5-12-, or 12-25-veined |
..........6 Perigynia 12-34-veined. |
............ 7 Basal and proximal leaf sheaths reddish or purplish |
............ 7 Basal and proximal leaf sheaths yellowish to brown, without trace of red or purple |
......4 Perigynia < 10 mm long. |
............ ..8 At least proximal pistillate scales with long, rough awn. |
............ ....9 Perigynia with 2 strong marginal veins, otherwise veinless or veined only proximally; leaves not septate-nodulose. |
............ ....9 Perigynia with 5+ strong veins extending length of bodies; leaves septate-nodulose. |
............ ......10 Perigynium beak with apical teeth (0.4-) 0.6-3 mm long, often > 1 mm long |
............ ......10 Perigynium beak with apical teeth < 1 mm long. |
............ ........11 Perigynium body obovoid, widest distally; proximal bract > 3× as long as the inflorescence |
............ ........11 Perigynium body ovoid or lanceoloid or ellipsoid, widest at middle or proximally; proximal bract usually < 2× as long as the inflorescence. |
............ ..........12 Perigynium beak 0.9-1.7 mm long; mature perigynia dull |
............ ..........12 Perigynium beak 0.2-6 mm long; mature perigynia somewhat glossy |
............ ..8 All pistillate scales obtuse to acuminate or cuspidate. |
............ ............ 13 Culms with some red or purple at base. |
............ ............ ..14 All perigynia erect or ascending; leaves not septate-nodulose |
............ ............ ..14 At least proximal perigynia in each spike spreading or reflexed; leaves sparsely septate-nodulose |
............ ............ 13 Culms brown or black at base, without trace of red or purple. |
............ ............ ....15 Pistillate scales with 5-7-veined center |
............ ............ ....15 Pistillate scales with 1-3-veined center. |
............ ............ ......16 Leaves not septate-nodulose |
............ ............ ......16 Leaves at least sparingly septate-nodulose |
1 Apex of perigynium beak entire, emarginate, or with teeth mostly < 0.5 mm long. |
............ ............ ........17 Leaf blades variously hairy. |
............ ............ ..........18 Plant brown or black at base |
............ ............ ..........18 Plant with at least some red or purple at base |
............ ............ ........17 Leaf blades glabrous. |
............ ............ ............ 19 Bracts without blades. |
............ ............ ............ ..20 Leaves < 1 mm wide |
............ ............ ............ ..20 Leaves much wider, often over 10 mm wide |
............ ............ ............ 19 Bracts, at least the proximal, with distinct blade. |
............ ............ ............ ....21 Young leaves V-shaped or rounded in cross section, adaxial surface without 2 marginal veins more prominent than midvein or other veins. |
............ ............ ............ ......22 Perigynium beak with 2 distinct terminal teeth, usually > 0.2 mm long. |
............ ............ ............ ........23 At least proximal pistillate scales awned, awn at least 1/2 as long as body; leaves conspicuously septate-nodulose. |
............ ............ ............ ..........24 Base of culm strongly red or purple; leaves 2-4 mm wide |
............ ............ ............ ..........24 Base of culm brown, without or with only trace of red or purple; leaves 4-15 mm wide. |
............ ............ ............ ............ 25 Distal pistillate scales acute, acuminate, or short-awned, awn less than 1/2 length of body |
............ ............ ............ ............ 25 Distal pistillate scales with awn at least about as long as body |
............ ............ ............ ........23 Pistillate scales obtuse to acuminate, sometimes very shortly awned; leaves not or only weakly septate-nodulose. |
............ ............ ............ ............ ..26 Plants with long-creeping rhizomes; leaves usually not septate-nodulose |
............ ............ ............ ............ ..26 Plants with short-ascending rhizomes; leaves at least sparingly septate-nodulose. |
............ ............ ............ ............ ....27 Proximal perigynia in each spike ascending or spreading-ascending |
............ ............ ............ ............ ....27 Proximal perigynia in each spike spreading or reflexed |
............ ............ ............ ......22 Perigynium beak entire, emarginate, or with 2 apical teeth < 0.2 mm long. |
............ ............ ............ ............ ......28 Perigynia rounded at base, sides proximally distinctly convex. |
............ ............ ............ ............ ........29 Perigynia with veins slightly prominent |
............ ............ ............ ............ ........29 Perigynia with veins slightly impressed |
............ ............ ............ ............ ......28 Perigynia tapering at base, sides straight or only slightly convex proximally. |
............ ............ ............ ............ ..........30 Perigynia rounded at apex, beakless or with beak < 0.3 mm long. |
............ ............ ............ ............ ............ 31 Widest leaf blades < 5 mm wide; plants usually not cespitose |
............ ............ ............ ............ ............ 31 Widest leaf blades usually > 5 mm wide; plants usually cespitose |
............ ............ ............ ............ ..........30 Perigynia tapering to beak at least > (0.3-) 0.5 mm long. |
............ ............ ............ ............ ............ ..32 Proximal perigynia in each spike spreading at right angles or reflexed at maturity; leaves and sheaths sparsely septate- nodulose |
............ ............ ............ ............ ............ ..32 Proximal perigynia in each spike ascending or spreading-ascending; leaves and sheaths not septate-nodulose. |
............ ............ ............ ............ ............ ....33 Plants usually colonial; perigynia and leaves often papillose |
............ ............ ............ ............ ............ ....33 Plants cespitose; perigynia and leaves not papillose |
............ ............ ............ ....21 Leaf blades M-shaped in cross section when young, adaxial surface with 2 marginal veins more prominent than midvein and other marginal veins, sometimes apparent only on proximal leaves and on proximal part of blade. |
............ ............ ............ ............ ............ ......34 Perigynium beakless or with beak < 0.5 mm long, entire or with 2 apical teeth < 0.1 mm long. |
............ ............ ............ ............ ............ ........35 Widest leaf blades (usually basal) > 10 mm wide. |
............ ............ ............ ............ ............ ..........36 Distal pistillate spikes strongly pendulous, perigynia > 100 per spike; [exotic] |
............ ............ ............ ............ ............ ..........36 Distal pistillate spikes erect, perigynia < 30 per spike; [native]. |
............ ............ ............ ............ ............ ............ 37 Perigynia trigonous with rounded angles in cross section |
............ ............ ............ ............ ............ ............ 37 Perigynia sharply trigonous in cross section |
............ ............ ............ ............ ............ ........35 Widest leaf blades < 10 mm wide. |
............ ............ ............ ............ ............ ............ ..38 Perigynia not prominently veined, veins somewhat impressed |
............ ............ ............ ............ ............ ............ ..38 Perigynia at least slightly prominently veined or veinless except for 2 marginal veins. |
............ ............ ............ ............ ............ ............ ....39 Perigynia rounded at base, sides proximally convex |
............ ............ ............ ............ ............ ............ ....39 Perigynia tapering at base, sides proximally straight, concave or slightly convex. |
............ ............ ............ ............ ............ ............ ......40 Perigynia transversely wrinkled; leaf sheaths sparsely septate-nodulose |
............ ............ ............ ............ ............ ............ ......40 Perigynia not transversely wrinkled; leaf sheaths not septate-nodulose. |
............ ............ ............ ............ ............ ............ ........41 Perigynia sharply trigonous in cross section |
............ ............ ............ ............ ............ ............ ........41 Perigynia terete or with rounded angles in cross section. |
............ ............ ............ ............ ............ ............ ..........42 Perigynia with 2 marginal veins and not more than 10 veins on faces |
............ ............ ............ ............ ............ ............ ..........42 Perigynia with more than 12 veins. |
............ ............ ............ ............ ............ ............ ............ 43 Plants usually colonial, not cespitose; perigynia papillose at least faintly. |
............ ............ ............ ............ ............ ............ ............ 43 Plants usually cespitose; perigynia not papillose. |
............ ............ ............ ............ ............ ......34 Perigynium with distinct beak > 0.5 mm, usually with apical teeth > 0.1 mm long. |
............ ............ ............ ............ ............ ............ ............ ..44 Perigynia with 2 distinct marginal veins, otherwise veinless or with very weak veins proximally. |
............ ............ ............ ............ ............ ............ ............ ....45 Perigynium beak entire, emarginate, or with apical teeth < 0.1 mm long |
............ ............ ............ ............ ............ ............ ............ ....45 Perigynium beak with apical teeth 0.2-1 mm. |
............ ............ ............ ............ ............ ............ ............ ......46 Perigynium beak usually < 1 mm long. |
............ ............ ............ ............ ............ ............ ............ ......46 Perigynium beak sometimes > 2 mm long |
............ ............ ............ ............ ............ ............ ............ ..44 Perigynia with more than 2 veins extending most of length of bodies. |
............ ............ ............ ............ ............ ............ ............ ........47 Pistillate scales with narrow, indistinct bodies, scarcely enlarged at bases |
............ ............ ............ ............ ............ ............ ............ ........47 Pistillate scales with wide, flat bodies, sometimes terminating in awns. |
............ ............ ............ ............ ............ ............ ............ ..........48 Perigynium beak entire or emarginate. |
............ ............ ............ ............ ............ ............ ............ ............ 49 Perigynium with not more than 5 veins extending length of body on abaxial face, veinless or weakly veined on adaxial face |
............ ............ ............ ............ ............ ............ ............ ............ 49 Perigynium with > 8 equally prominent veins on both faces. |
............ ............ ............ ............ ............ ............ ............ ............ ..50 Perigynia bluntly angled in cross section |
............ ............ ............ ............ ............ ............ ............ ............ ..50 Perigynia sharply angled in cross section |
............ ............ ............ ............ ............ ............ ............ ..........48 Perigynium beak with 2 distinct teeth at apex, usually > 0.2 mm long. |
............ ............ ............ ............ ............ ............ ............ ............ ....51 Pistillate spikes, at least the proximal, lax, proximal and middle perigynia separated by internodes at least 1/4 their length; leaves and sheaths not septate-nodulose |
............ ............ ............ ............ ............ ............ ............ ............ ....51 Pistillate spikes dense, proximal and middle perigynia separated by internodes less than 1/10 their length; proximal leaves and sheaths sparingly septate-nodulose. |
............ ............ ............ ............ ............ ............ ............ ............ ......52 Pistillate scales, at least proximal, awned, awn at least 1/4 of scale body length. |
............ ............ ............ ............ ............ ............ ............ ............ ........53 Distal pistillate scales acuminate or with awn less than 1/2 body length; staminate spikes usually 2+ |
............ ............ ............ ............ ............ ............ ............ ............ ........53 Distal pistillate scales awned, awn usually more than 1/2 body length; staminate spikes 1, sometimes with 1 much smaller spike laterally |
............ ............ ............ ............ ............ ............ ............ ............ ......52 Pistillate scales obtuse to acute or apiculate, apiculus not more than 1/10 of body length. |
............ ............ ............ ............ ............ ............ ............ ............ ..........54 Culms purple-red at base; achenes with style persistent |
............ ............ ............ ............ ............ ............ ............ ............ ..........54 Culms brown at base, without trace of red or purple; achenes with style deciduous |