Home Flora of Missouri
Home
Name Search
Families
Volumes
!!Carex L. Search in The Plant ListSearch in IPNISearch in Australian Plant Name IndexSearch in Index Nominum Genericorum (ING)Search in NYBG Virtual HerbariumSearch in JSTOR Plant ScienceSearch in SEINetSearch in African Plants Database at Geneva Botanical Garden Decrease font Increase font Restore font
 

Published In: Species Plantarum 2: 972. 1753. (1 May 1753) (Sp. Pl.) Name publication detailView in BotanicusView in Biodiversity Heritage Library
 

Project Name Data (Last Modified On 9/1/2009)
Acceptance : Accepted
 

Export To PDF Export To Word

85. Carex nebrascencis Dewey

Pl. 52 e–h; Map 201

Plants with long-creeping rhizomes, forming large or more commonly small clumps. Flowering stems 20–30(–90) cm long, mostly shorter than the leaves, erect to ascending, sharply trigonous, usually roughened toward the tip, brown or sometimes reddish tinged at the base. Leaves all with well-developed blades (except the scalelike leaves of the rhizomes), the partially degraded remains of the basal leaves of the previous year persistent, brown. Leaf blades 10–30(–40) cm long, 3–5(–8) mm wide, light green and often glaucous. Leaf sheaths with the tip concave, the ligule about as long as wide, the ventral side not dissected into a network of fibers, white to yellowish brown, the lowermost sheaths brown or sometimes reddish tinged. Spikes 3–6 per stem, the lowermost bract about as long as the inflorescence. Staminate spike(s) 1(2), 15–25(–45) mm long, sessile or short-stalked. Staminate scales 3.5–4.5 mm long, oblong-obovate, rounded to bluntly pointed at the tip, awnless, brown to reddish brown or purplish black with lighter midrib and white margins. Pistillate spikes 2–5, ascending, the uppermost sometimes with a few staminate flowers at the tip, 20–25(–55) mm long, 5–7 mm wide. Pistillate scales 3.5–5.0 mm long, narrowly elliptic-ovate, pointed to short-awned at the tip, purplish brown to dark brown with lighter, sometimes green midrib and usually white margins. Perigynia 2.7–3.5 mm long, elliptic to obovate in outline, flattened and biconvex in cross-section, sometimes slightly inflated dorsally, with a beak 0.3–0.6 mm long with a pair of noticeable teeth at the tip, the surfaces each with 5–9 strong nerves in addition to the 2 marginal ribs, green to straw-colored or brown, sometimes with reddish brown dots. Styles withering during fruit development and jointed to the main body of the fruit. Fruits 1.4–1.9 mm long, elliptic to obovate in outline, minutely beaked at the tip, brown to nearly black. 2n=66, 68. May–July.

Introduced, known only from St. Louis (western U.S. and adjacent Canada east to Kansas). Railroads.

The specific epithet has been spelled “nebraskensis” in some of the botanical literature (Steyermark, 1963), but Dewey’s original spelling should be preserved.

 

Export To PDF Export To Word Export To SDD
Switch to indented key format
1 Aerial stems with only 1 spike (do not confuse densely spaced, multiple spikes for single spikes) (2)
+ Aerial stems with 2 or more spikes (5)
2 (1) Spike with all staminate or all pistillate flowers 1 Carex sect. Acrocystis
+ Spike with both staminate and pistillate flowers (3)
3 (2) Spike with the staminate flowers toward the base 28 Carex sect. Squarrosae
+ Spike with the staminate flowers toward the tip (4)
4 (3) Lowermost pistillate scale 15–50 mm long, leaflike 24 Carex phyllostachys
+ Pistillate scales 2.5–5.0 mm long, not leaflike 25 Carex sect. Polytrichoideae
5 (1) Stigmas 2; fruits biconvex, sometimes unevenly so (1 side flat, the other rounded) (6)
+ Stigmas 3; fruits slightly to strongly trigonous, sometimes circular in cross-section or nearly so (23)
6 (5) Some or all of the spikes completely staminate or completely pistillate, distinctly different in size and appearance, or the plants dioecious (7)
+ All spikes more or less similar in size and appearance, usually containing both staminate and pistillate flowers (except in section Stellulatae) (10)
7 (6) Inflorescences open to somewhat dense, the spikes all distinctly separated, mostly 3–20 times as long as wide (8)
+ Inflorescences very dense, composed of a more or less continuous cluster of short spikes that are 1–2 times as long as wide, the individual spikes sometimes difficult to differentiate (9)
8 (7) Pistillate spikes 30–110 mm long, with numerous perigynia 22 Carex sect. Phacocystis
+ Pistillate spikes 3–13 mm long, with 5–25 perigynia 29 Carex sect. Stellulatae
9 (7) Leaves all clustered near the base of the plant, 1–3 mm wide, the sheaths white to light brown on the ventral side, unlined 9 Carex sect. Divisae
+ Leaves basal and noticeably alternate along the lower half of the aerial stems, 2–5 mm wide, the sheaths mostly green and with a fine pattern of vertical, green lines along the ventral side 14 Carex sect. Intermediae
10 (6) Plants with the rhizomes well developed and long-creeping, forming loose colonies of tufts, or the aerial stems well spaced and not tufted (11)
+ Plants with the rhizomes short-creeping or poorly developed, forming dense tufts or clumps (13)
11 (10) Inflorescences open, the spikes all or mostly distinctly separated 23 Carex sect. Phaestoglochin
+ Inflorescences very dense, the individual spikes sometimes difficult to differentiate (12)
12 (11) Leaves basal and noticeably alternate along the lower half of the aerial stems, 2–5 mm wide, the sheaths mostly green and with a fine pattern of vertical, green lines along the ventral side 14 Carex sect. Intermediae
+ Leaves all clustered near the base of the plant, 1–3 mm wide, the sheaths white to light brown on the ventral side, unlined 9 Carex sect. Divisae
13 (10) Staminate flowers at the bases of some or all of the spikes (if stamens have fallen from older spikes, locate the position of the densely overlapping or empty scales of the staminate portions), the spikes often appearing tapered at the base (14)
+ Staminate flowers at the tips of some or all of the spikelets (if stamens have fallen from older spikes, locate the position of the densely overlapping or empty scales of the staminate portions), the spikes usually appearing abruptly rounded or truncate at the base (17)
14 (13) Perigynia flattened, the margins with prominent, thin wings, at least on the beak and apical portion of the body (15)
+ Perigynia plump, or if somewhat flattened then the margins rounded to angled or narrowly ridged, but not winged (16)
15 (14) Bracts leaflike, much longer than the inflorescence (to 20 cm long) 7 Carex cyperoidea
+ Bracts reduced, shorter and narrower than the leaves, shorter than the inflorescence or nearly so 18 Carex sect. Ovales
16 (14) Perigynia all ascending to nearly erect 8 Carex sect. Deweyanae
+ Perigynia mostly spreading or reflexed, occasionally ascending 29 Carex sect. Stellulatae
17 (13) Perigynia thin-walled, with the base noticeably corky- or spongy-thickened at maturity (test base with a needle or forceps to see mass of soft tissue around the base of the fruit) (18)
+ Perigynia thick- or thin-walled, but not noticeably corky- or spongy-thickened at the base (sometimes slightly and inconspicuously spongy-based in section Phaestoglochin) (20)
18 (17) Spikes more than 10 per inflorescence, usually numerous, at least the lowermost nodes usually with more than 1 spike (inflorescence compound) 32 Carex sect. Vulpinae
+ Spikes mostly less than 10 per inflorescence, 1 per node (inflorescence unbranched) (19)
19 (18) Lateral spikes with both pistillate and staminate flowers, the staminate flowers relatively few and inconspicuous; perigynia green, straw-colored, or less commonly tan at maturity 23 Carex sect. Phaestoglochin
+ Lateral spikes mostly all staminate or all pistillate, less commonly with a few pistillate flowers scattered in an otherwise staminate spike; perigynia turning brown at maturity 29 Carex sect. Stellulatae
20 (17) Inflorescence compound, with lower branches conspicuous, to 4 cm long; perigynia dark brown to olive green or nearly black at maturity 12 Carex sect. Heleoglochin
+ Inflorescence unbranched, or if compound then the lower nodes with the clusters of spikes sessile or on short branches; perigynia green, straw-colored, yellow, tan, or brown at maturity (21)
21 (20) Inflorescences compound, the lowermost nodes with 2 or more spikes; spikes numerous; stems bluntly to sharply trigonous, but firm and not winged 17 Carex sect. Multiflorae
+ Inflorescences with the spikes 1 per node, or if compound then the stems sharply trigonous, narrowly winged, and easily crushed; if the inflorescence is too dense to distinguish the number of spikes per node, then the spikes 10 or fewer (22)
22 (21) Lateral spikes with both pistillate and staminate flowers, the staminate flowers relatively few and inconspicuous; perigynia green, straw-colored, or less commonly tan at maturity 23 Carex sect. Phaestoglochin
+ Lateral spikes mostly all staminate or all pistillate, less commonly with a few pistillate flowers scattered in an otherwise staminate spike; perigynia turning brown at maturity 29 Carex sect. Stellulatae
23 (5) All or part of the leaf sheaths, leaf blades, bracts, and/or aerial stems hairy (plants that are otherwise glabrous, with leaves or stems minutely roughened or finely toothed along the margins, should be keyed as being glabrous) (24)
+ Leaf sheaths, leaf blades, bracts, and aerial stems glabrous (leaves or stems sometimes minutely roughened or finely toothed along the margins) (30)
24 (23) Perigynia with the body hairy (25)
+ Perigynia with the body glabrous (beaks sometimes minutely roughened or toothed) (26)
25 (24) Terminal spike entirely staminate 30 Carex sect. Triquetrae
+ Terminal spike mostly pistillate, with staminate flowers at the base 26 Carex sect. Porocystis
26 (24) Terminal spike entirely staminate (rarely a few pistillate flowers present at tip or base) (27)
+ Terminal spike with pistillate flowers toward the tip and staminate flowers toward the base (29)
27 (26) Plants with the rhizomes well developed and long-creeping, forming loose colonies, the aerial stems well spaced; perigynia 7–12 mm long 5 Carex sect. Carex
+ Plants with the rhizomes short-creeping or poorly developed, forming dense tufts or clumps; perigynia 4.5–7.0 mm long (28)
28 (27) Pistillate spikes with 2–8 perigynia; basal leaf sheaths brown, lacking reddish purple or purple coloration 11 Carex sect. Griseae
+ Pistillate spikes with 9–25 perigynia; basal leaf sheaths tinged with reddish purple or purple 13 Carex sect. Hymenochlaenae
29 (26) Lateral spikes 18–45 mm long, 6–8 times as long as broad, linear to narrowly oblong in outline 13 Carex sect. Hymenochlaenae
+ Lateral spikes 5–20 mm long, 1–4 times as long as broad, narrowly ovate to narrowly oblong in outline 26 Carex sect. Porocystis
30 (23) Perigynia with the body hairy or roughened with minute, stiff hairs (perigynia with bodies minutely pebbled, papillose, or resin-dotted should be keyed as being glabrous) (31)
+ Perigynia with the body glabrous (beaks sometimes minutely roughened or toothed, or bodies occasionally minutely pebbled or papillose) (37)
31 (30) Perigynia 12–20 mm long; pistillate spikes 20–40 mm wide 16 Carex sect. Lupulinae
+ Perigynia less than 10 mm long; pistillate spikes less than 15 mm wide (32)
32 (31) Flowering stems 1–20 cm long, most or all of them shorter than and/or hidden by the leaf blades 1 Carex sect. Acrocystis
+ Flowering stems 20–120 cm long, or if shorter than 20 cm then longer than and not hidden by the leaf blades (33)
33 (32) Terminal spike with pistillate flowers toward the tip and staminate flowers toward the base 26 Carex sect. Porocystis
+ Terminal spike entirely staminate (34)
34 (33) Pistillate spikes 3–9 mm long, 1–2 times as long as wide; aerial stems 5–50 cm long 1 Carex sect. Acrocystis
+ Pistillate spikes 10–90 mm long, 3–6 times as long as wide; aerial stems 40–90 cm long (35)
35 (34) Perigynia roughened with minute, stiff hairs, the beak somewhat curved; basal leaf sheaths lacking reddish purple to purple coloration 3 Carex sect. Anomalae
+ Perigynia not roughened, lacking a beak or the beak straight; basal leaf sheaths tinged with reddish purple or purple (36)
36 (35) Perigynia 5–10 mm long, tapering to a prominent beak ending in 2 teeth 0.9–3.0 mm long 5 Carex sect. Carex
+ Perigynia 3.0–4.5 mm long, narrowed abruptly to a short beak ending in 2 teeth 0.3–0.9 mm long 19 Carex sect. Paludosae
37 (30) Terminal spike with pistillate flowers toward the tip and staminate flowers toward the base (38)
+ Terminal spike entirely staminate or with a few perigynia at the base (note that the terminal spike may sometimes be overtopped by longer or stalked, lateral, pistillate spikes) (42)
38 (37) Spikes 10–22 mm wide at maturity; perigynia 3.5–8.5 mm long 28 Carex sect. Squarrosae
+ Spikes 2–8 mm wide at maturity; perigynia 2–4 mm long (39)
39 (38) Perigynia with distinct, well-developed beaks; at least some of the lowermost spikes spreading to drooping and long-stalked 13 Carex sect. Hymenochlaenae
+ Perigynia lacking beaks or with short, poorly developed beaks; spikes all erect or ascending (40)
40 (39) Perigynia grayish white, the surface minutely pebbled or papillose; plants with well-developed, long-creeping rhizomes, not forming dense tufts or clumps 4 Carex sect. Atratae
+ Perigynia olive green to dark brown, the surface not pebbled or papillose; plants with short-creeping or poorly developed rhizomes, forming dense tufts or clumps (41)
41 (40) Perigynia distinctly longer than wide, with 1 or more nerves, ascending on the spike 26 Carex sect. Porocystis
+ Perigynia about as long as wide, nerveless, spreading at a right angle to the axis of the spike 27 Carex sect. Shortianae
42 (37) Perigynia 10–20 mm long at maturity 16 Carex sect. Lupulinae
+ Perigynia 2–9(–10) mm long at maturity (43)
43 (42) Lowermost (or only) pistillate spike with the bract absent or reduced to a tubular sheath, the blade absent or short-triangular (do not confuse the bract of the spike with the lowermost pistillate scale, which subtends a perigynium and may be leaflike in section Phyllostachys) (44)
+ Lowermost pistillate spike with the bract having a well-developed, leaflike blade (the sheath may be absent or present) (46)
44 (43) Spikes all staminate toward the tip and with 2–4 perigynia toward the base, the lowermost (or only) spike without a bract; however, the lowermost pistillate scale 15–50 mm long, leaflike 24 Carex phyllostachys
+ Terminal spike entirely staminate or rarely with a few perigynia at the base, the other spike(s) all pistillate; lowermost (or only) pistillate spike with the bract reduced to a tubular sheath, the blade absent or short-triangular; pistillate scales 1.2–4.0 mm long, not leaflike (45)
45 (44) Pistillate spikes mostly basal and long-stalked, often hidden among the leaf bases, but when associated with a staminate spike, then 1–2, sessile, and not overtopping the terminal, staminate spike; perigynia 2.5–4.0 mm long 1 Carex sect. Acrocystis
+ Pistillate spikes 2–4, lateral, on long stalks and overtopping the staminate spike; perigynia 1.5–2.0 mm long 2 Carex sect. Albae
46 (43) Pistillate spikes with 1–9 perigynia (47)
+ Pistillate spikes with 10 to numerous perigynia (50)
47 (46) Perigynia pale green, usually glaucous; plants with the rhizomes well developed and long-creeping, the aerial stems mostly arising singly 20 Carex sect. Paniceae
+ Perigynia olive green to dark green or brown, not glaucous; plants with the rhizomes short-creeping or poorly developed (except in C. abscondita of the Careyanae), the aerial stems arising from tufts or clumps (48)
48 (47) Perigynia with the numerous nerves impressed (most easily seen in dried specimens); pistillate scales with rough-margined awns 11 Carex sect. Griseae
+ Perigynia with the usually numerous nerves raised; pistillate scales lacking awns or with the awns smooth-margined (49)
49 (48) Perigynia sharply trigonous with the sides flat or nearly so and with more than 40 nerves 6 Carex sect. Careyanae
+ Perigynia bluntly trigonous with the sides convex, at least in the lower half and with 25 or fewer nerves 15 Carex sect. Laxiflorae
50 (46) Styles persistent, not jointed to and forming a hard, bony beak similar in texture to the main body of the fruit; perigynia usually prominently beaked, the beak ending in 2 stiff, short to long teeth (51)
+ Styles withering during fruit development, jointed to the main body of the fruit, which is beakless or short-beaked at maturity; perigynia lacking a beak or with the beak lacking well-developed teeth at the tip, appearing cut-off or with short, soft, inconspicuous teeth (55)
51 (50) Staminate spike 1 per inflorescence (52)
+ Staminate spikes 2–6 per inflorescence (53)
52 (51) Perigynia with the main body obovate to obtriangular in outline, widest above the middle, truncate or abruptly narrowed to the beak 28 Carex sect. Squarrosae
+ Perigynia narrowly to broadly ovate in outline, widest at or below the middle, tapered more or less gradually to the beak 31 Carex sect. Vesicariae
53 (51) Plants with the rhizomes short-creeping or poorly developed, forming dense tufts or clumps; perigynia thin-walled, papery 31 Carex sect. Vesicariae
+ Plants with the rhizomes well developed and long-creeping, forming large colonies; perigynia thick-walled, firm or leathery (54)
54 (53) Perigynia with teeth 1.0–2.2 mm long; fruits with the stylar beak straight at maturity 5 Carex sect. Carex
+ Perigynia with the teeth 0.3–1.0 mm long; fruits with the stylar beak bent or curved abruptly near the base 19 Carex sect. Paludosae
55 (50) Bract of the lowest pistillate spike lacking a sheath or nearly so 21 Carex [ unranked ] Pendulinae
+ Bract of the lowest pistillate spike (not to be confused with the scales of the lowermost perigynia) with a well-developed, tubular sheath (56)
56 (55) At least the lowermost pistillate spike with long, thin stalks, spreading, nodding, or drooping at maturity (57)
+ Spikes variously sessile or stalked, but all erect or ascending (58)
57 (56) Pistillate spikes mostly spreading, nodding, or drooping, 20–60 mm long, or if less than 20 mm long then the perigynia abruptly narrowed to a slender beak about as long as the main body 13 Carex sect. Hymenochlaenae
+ Pistillate spikes mostly erect to ascending, only the lowermost spreading, 6–20 mm long; perigynia without beaks or with tapered beaks much shorter than the main body 15 Carex sect. Laxiflorae
58 (56) Plants with the rhizomes well developed and long-creeping, the aerial stems mostly arising singly (59)
+ Plants with the rhizomes short-creeping or poorly developed, forming tufts or clumps (60)
59 (58) Perigynia green to brown, not pale or glaucous, broadest at or below the middle, rounded at the base, loosely enveloping the fruit; leaf blades smooth on the undersurface 10 Carex sect. Granulares
+ Perigynia pale green to pale brown or nearly white, often somewhat glaucous, broadest above the middle, tapered at the base, tightly enveloping the fruit; leaf blades with minute papillae on the undersurface 20 Carex sect. Paniceae
60 (58) Perigynia with the nerves impressed (more easily seen in dried specimens) 11 Carex sect. Griseae
+ Perigynia with the nerves raised (61)
61 (60) Perigynia rounded at the base, obscurely trigonous to nearly circular in cross-section; stems bluntly trigonous, firm and not easily compressed 10 Carex sect. Granulares
+ Perigynia tapered at the base, strongly trigonous in cross-section, but with convex sides, at least below the middle; stems strongly trigonous, soft and easily compressed 15 Carex sect. Laxiflorae
 

Lower Taxa
 
 
© 2014 Missouri Botanical Garden - 4344 Shaw Boulevard - Saint Louis, Missouri 63110