The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links
Photo is of parent taxon

carex disjoint, disjunct hoary sedge, silvery sedge

Habit Plants loosely to densely cespitose, rhizomatous (stoloniferous in C. mackenziei).
Culms

30–90 cm.

brown at base.

Leaves

basal sheaths fibrous, usually not persisting more than a year;

sheath fronts membranous;

blades V-shaped in cross section when young, glabrous.

Inflorescences

6–12(–15) cm, all but distalmost spikes distant, proximal 2 spikes 2–5 cm apart.

racemose, with (1–)2–10(–15) spikes;

rachis of spikes glabrous;

proximal bracts scalelike, bristlelike, or inconspicuous, sheathless;

lateral spikes gynecandrous or pistillate, sessile, without prophylls;

terminal spikes gynecandrous.

Perigynia

ascending or spreading, obscurely to distinctly veined on both faces, stipitate, obovate, ovate, lanceolate, or elliptic, plano-convex in cross section, 1.5–4 mm, base rounded or truncate, with spongy tissue, margins rounded or acutely angled, apex rounded and beakless or abruptly beaked, smooth or minutely papillose, glabrous;

beak sometimes inconspicuous, 0.1–0.3 mm, with or without abaxial suture, margins entire or sparsely and minutely serrulate, apex entire or bidentate.

Achenes

biconvex, smaller than bodies of perigynia;

style deciduous.

Proximal

pistillate scales with apex obtuse to acute or cuspidate.

Stigmas

2.

x

= 27–33.

2n

= 54.

Carex canescens subsp. disjuncta

Carex sect. Glareosae

Phenology Fruiting Apr–Jul.
Habitat Wet, usually base-poor habitats, such as sphagnum bogs, moist coniferous forests and meadows, from lowlands to near the timberline in mountains
Elevation 0–3500 m (0–11500 ft)
Distribution
from FNA
CT; DC; DE; IL; IN; MA; MD; ME; MI; MN; NC; NH; NJ; NY; OH; PA; RI; SC; VA; VT; WI; NB; NL; NS; ON; PE; QC; SPM
[BONAP county map]
South America; Circumboreal; high montane regions of North America; Eurasia; Australia; and New Zealand
Discussion

Carex canescens subsp. disjuncta is a dominating subspecies in the southern part of the range of the species in eastern North America; it grades into subsp. canescens in northern areas. Subspecies disjuncta differs from subsp. canescens in its longer culms (to 90 cm), leaves, inflorescences [1–12(–15) cm], and spikes. The subglobular spikes are often more numerous and the proximal separated by 2–5 cm. The perigynia are slightly longer, clearly wider and more abruptly beaked than in the type subspecies.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Species 20–25 (16 in flora).

Members of Carex sect. Glarosae primarily occur on peatlands, shores, meadows, moist forests, and wet tundra in the colder parts of the flora area and extend northward into the arctic region and southward in the western mountains. The group is widely distributed in Eurasia and sparingly represented in the mountains of southern Asia, North America, South America, Australia, and New Zealand.

Hybrids in sect. Glareosae are rather uncommon, though to some extent neglected. Hybrids are found where parental species coexist, and they usually show intermediate ecologic preferences (H. Toivonen 1981). Hybrids are intermediate in morphology and some show hybrid vigor. They seem to be highly sterile with aborted pollen grains and empty perigynia.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Proximal bracts long-bristlelike, many times exceeding 1–5-flowered spike; spikes widely separate.
C. trisperma
1. Proximal bracts short-bristlelike or scalelike, often shorter than spike; spikes usually several-flowered, distal spikes approximate.
→ 2
2. Perigynia beakless or nearly so; scales white-hyaline; plants loosely cespitose.
→ 3
2. Perigynia shortly to strongly beaked; scales green or brown; plants loosely or densely cespitose.
→ 4
3. Perigynia gray-green; spikes aggregated, forming an ovoid to suborbicular head; perigynia obscurely veined.
C. tenuiflora
3. Perigynia light green; spikes remote (proximal 2 spikes at least 1 cm apart); perigynia conspicuously veined.
C. loliacea
4. Perigynia widest near base, apex long-beaked, margins strongly serrulate.
C. arcta
4. Perigynia widest near middle, apex short-to long-beaked, margins entire to serrulate.
→ 5
5. Spikes 1–4(–6), closely approximate; scales tinged chestnut or red.
→ 6
5. Spikes 3–10, approximate to remote; scales tinged light green or dark brown.
→ 10
6. Culms 2–10 cm; plants densely cespitose; leaves exceeding culms; spike 1(–2).
C. ursina
6. Culms more than 10 cm; plants usually loosely cespitose; leaves usually shorter than culms; spikes 2–4(–6).
→ 7
7. Culms often arching; leaves 1–2 mm wide, flat to channeled, gray-green; lateral spikes pistillate; perigynia gray-brown to pale brown at maturity.
C. glareosa
7. Culms erect; leaves 1–3 mm wide, flat, green or gray-green; lateral spikes gynecandrous; perigynia brownish at maturity.
→ 8
8. Culms smooth or nearly so; leaves green; perigynia brownish yellow, apex distinctly beaked.
C. lachenalii
8. Culms rough distally; leaves gray-green; perigynia gray-green or at maturity brown, apex scarcely to distinctly beaked.
→ 9
9. Spikes 3–4(–6), 5–10 mm, ovoid-globose; beak distinct.
C. heleonastes
9. Spikes 2–3(–4), 3–6 mm, oblong-clavate; beak indistinct.
C. marina
10. Terminal spike clearly clavate, staminate for at least 1/2 of length; pistillate scales equaling or exceeding, partly concealing perigynia.
C. mackenziei
10. Terminal spike not or scarcely clavate, staminate for less than 1/2 of length; pistillate scales shorter than, not concealing perigynia.
→ 11
11. Perigynia loosely spreading, distinctly beaked, with long, asymmetric abaxial suture conspicuous; leaves green to yellowish green.
C. brunnescens
11. Perigynia appressed-ascending, very shortly to distinctly beaked, abaxial suture inconspicuous; leaves usually gray-green.
→ 12
12. Perigynia 1.5–1.8 mm; scales tinged brown or chestnut-brown.
→ 13
12. Perigynia 1.8–3.5 mm; scales hyaline with green center, usually tinged brown at maturity.
→ 14
13. Spikes 5–8, proximal spikes separate, distal approximate.
C. bonanzensis
13. Spikes 3–5, ± approximate.
C. praeceptorum
14. Spikes closely approximate; scales somewhat concealing perigynia; perigynia often dark brown at maturity.
C. arctiformis
14. Spikes, at least the proximal, remote; scales not concealing perigynia; perigynia usually light brown at maturity.
→ 15
15. Leaves (1.5–)2–4 mm wide; perigynia 1.8–3 mm; beak with small marginal teeth.
C. canescens
15. Leaves 1–2 mm wide; perigynia 1.7–2.1 mm; beak entire, without marginal teeth.
C. lapponica
Source FNA vol. 23, p. 318. FNA vol. 23. Author: Heikki Toivonen.
Parent taxa Cyperaceae > Carex > sect. Glareosae > Carex canescens Cyperaceae > Carex
Sibling taxa
C. canescens subsp. canescens
Subordinate taxa
C. arcta, C. arctiformis, C. bonanzensis, C. brunnescens, C. canescens, C. glareosa, C. heleonastes, C. lachenalii, C. lapponica, C. loliacea, C. mackenziei, C. marina, C. praeceptorum, C. tenuiflora, C. trisperma, C. ursina
Synonyms C. canescens var. disjuncta, C. disjuncta
Name authority (Fernald) Toivonen: Ann. Bot. Fenn. 18: 94. (1981) G. Don: in J. C. Loudon, Hort. Brit., 376. (1830)
Web links