OregonFlora: Carex geyeri vs. Cyperaceae

	Carex geyeri	Cyperaceae
	elk sedge	sedge family
Habit	Plants loosely cespitose or short rhizomatous, with thick, dark, shallow rhizomes; culms 12–50 cm, triangular in cross section.	Herbs annual or perennial; cespitose or not, rhizomatous or not, rarely stoloniferous.
Culms		usually triangular, occasionally terete, rarely compressed or quadrangular; solid or pithy.
Leaves	1.1–3.5 mm wide; flat; evergreen; leathery; as long as or longer than the culms.	basal and/or cauline, alternate, usually 3-ranked, bases forming cylindric sheaths enclosing stem; margins fused; ligules often present; blades frequently absent from some basal leaves, rarely from cauline leaves; when present flat, folded, rolled, or terete, linear.
Inflorescences	spike solitary, androgynous, lacking inflorescence bracts; male terminal portion 1–2.5 cm long, separated from the 1–3 perigynia by a short internode.
Spikes		with a shortened axis; floral scales 1–many, crowded, spirally arranged, sometimes 2-ranked, usually each subtending a single flower or perigynium, sometimes proximal and/or distal scales empty; perigynia if present closed or open down one side, subtending and enclosing a very short rachilla-bearing 1-pistillate flower (Carex), sometimes also (0)3 staminate flowers and empty scales (Kobresia); spikes aggregated into secondary inflorescences that are panicles, often modified and sometimes consisting of a single spike; secondary inflorescences usually subtended by a foliaceous or scale-like or bristle-like bract.
Flowers		bisexual (unisexual in Carex and Kobresia); perianth absent or consisting of (1)3–6(30) bristles and/or scales; stamens usually (1)3, rarely more; ovary with 1–3(4) carpels, fused; locule 1; style undivided or branched; stigmas 2–3(4).
Perigynia	obovate, rounded at the top, 5–7(8.5) × 1.8–2.8 mm, green; whitish, or brown; beak small; stigmas 3.
Fruits		achenes, usually trigonous or biconvex.
Achenes	trigonous.
Female scales	the lower longer than the perigynia; the upper reduced; more or less brown with paler midrib and margins, pointed to awned.

	Carex geyeri	Cyperaceae
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion	Well-drained soils in dry, open, conifer forests, aspen stands, and openings, rarely in sagebrush, on both serpentine and nonserpentine substrates. 100–2500 m. BR, BW, Col, ECas, Lava, Owy, Sisk. CA, ID, NV, WA; north to southeastern British Columbia, east to CO, PA. Native. Carex geyeri is a common ground cover in open forest, especially in northeastern Oregon, recognized by its tough, flat, evergreen leaves from dark, scaly rhizomes. Similar pinegrass, Calamagrostis rubescens, usually has hairy internodes and when in flower it is easily distinguished. Carex geyeri is important food for wildlife and livestock, especially in winter. In southwestern Oregon, C. geyeri can be confused with C. multicaulis, which is densely cespitose and has proportionately shorter, usually involute leaves, and longer, green, leaf-like, lower female scales.	Cosmopolitan. Approximately 100 genera; 16 genera treated in Flora. Cyperaceae (except Eleocharis) is characterized by unusual holocentric chromosomes, in which spindle fibers attach throughout the length of the chromosome, not at discrete centromeres. Also, reduction of chromosome number occurs at the second division of meiosis. These traits are shared with the related family Juncaceae but not by other vascular plants. Chromosome numbers in sedges are often very high, but it is unclear if this represents polyploidy or fragmentation of holocentric chromosomes. When collecting sedges, get the rhizomes (if present) because some species are distinguished by their cespitose or rhizomatous growth form. If possible, collect extra inflorescences because checking floral traits can be destructive. In some genera, species identification requires mature fruits.
Source	Flora of Oregon, volume 1, page 202 Barbara Wilson, Richard Brainerd, Nick Otting	Flora of Oregon, volume 1, page 167
Sibling taxa	C. abrupta, C. agastachys, C. amplifolia, C. angustata, C. aperta, C. aquatilis, C. arcta, C. arenaria, C. atherodes, C. athrostachya, C. atrosquama, C. aurea, C. barbarae, C. bebbii, C. bolanderi, C. brainerdii, C. brevior, C. breweri, C. buchananii, C. buxbaumii, C. californica, C. canescens, C. capillaris, C. capitata, C. chordorrhiza, C. comans, C. comosa, C. concinna, C. concinnoides, C. cordillerana, C. crawfordii, C. cusickii, C. davyi, C. deflexa, C. densa, C. diandra, C. disperma, C. distans, C. douglasii, C. duriuscula, C. echinata, C. exsiccata, C. feta, C. filifolia, C. fissuricola, C. fracta, C. gynocrates, C. gynodynama, C. halliana, C. harfordii, C. hassei, C. haydeniana, C. hendersonii, C. heteroneura, C. hirsutella, C. hirta, C. hoodii, C. hystericina, C. idahoa, C. illota, C. infirminervia, C. inops, C. integra, C. interior, C. interrupta, C. jonesii, C. kelloggii, C. klamathensis, C. kobomugi, C. laeviculmis, C. lasiocarpa, C. leporina, C. leporinella, C. leptalea, C. leptopoda, C. limosa, C. livida, C. longii, C. luzulina, C. lyngbyei, C. macrocephala, C. macrochaeta, C. media, C. mendocinensis, C. mertensii, C. mesochorea, C. micropoda, C. microptera, C. multicaulis, C. nardina, C. nebrascensis, C. nervina, C. neurophora, C. nigricans, C. nudata, C. obnupta, C. pachycarpa, C. pachystachya, C. pansa, C. paysonis, C. pellita, C. pelocarpa, C. pendula, C. petasata, C. phaeocephala, C. pluriflora, C. praeceptorum, C. praegracilis, C. praticola, C. preslii, C. pumila, C. raynoldsii, C. retrorsa, C. rossii, C. saxatilis, C. scabriuscula, C. scirpoidea, C. scoparia, C. scopulorum, C. serpenticola, C. serratodens, C. sheldonii, C. simulata, C. spectabilis, C. stipata, C. straminiformis, C. subbracteata, C. subfusca, C. subnigricans, C. sychnocephala, C. tahoensis, C. tiogana, C. tribuloides, C. tumulicola, C. unilateralis, C. utriculata, C. vallicola, C. vernacula, C. vesicaria, C. viridula, C. vulpinoidea, C. whitneyi, C. zikae
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: CA, OR Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Cyperaceae

elk sedge

sedge family

Habit

Plants loosely cespitose or short rhizomatous, with thick, dark, shallow rhizomes; culms 12–50 cm, triangular in cross section.

Herbs annual or perennial; cespitose or not, rhizomatous or not, rarely stoloniferous.

Culms

usually triangular, occasionally terete, rarely compressed or quadrangular; solid or pithy.

Leaves

1.1–3.5 mm wide; flat; evergreen; leathery; as long as or longer than the culms.

basal and/or cauline, alternate, usually 3-ranked, bases forming cylindric sheaths enclosing stem;

margins fused;

ligules often present;

blades frequently absent from some basal leaves, rarely from cauline leaves; when present flat, folded, rolled, or terete, linear.

Inflorescences

spike solitary, androgynous, lacking inflorescence bracts; male terminal portion 1–2.5 cm long, separated from the 1–3 perigynia by a short internode.

Spikes

with a shortened axis; floral scales 1–many, crowded, spirally arranged, sometimes 2-ranked, usually each subtending a single flower or perigynium, sometimes proximal and/or distal scales empty; perigynia if present closed or open down one side, subtending and enclosing a very short rachilla-bearing 1-pistillate flower (Carex), sometimes also (0)3 staminate flowers and empty scales (Kobresia);

spikes aggregated into secondary inflorescences that are panicles, often modified and sometimes consisting of a single spike; secondary inflorescences usually subtended by a foliaceous or scale-like or bristle-like bract.

Flowers

bisexual (unisexual in Carex and Kobresia);

perianth absent or consisting of (1)3–6(30) bristles and/or scales;

stamens usually (1)3, rarely more;

ovary with 1–3(4) carpels, fused; locule 1;

style undivided or branched;

stigmas 2–3(4).

Perigynia

obovate, rounded at the top, 5–7(8.5) × 1.8–2.8 mm, green; whitish, or brown;

beak small;

stigmas 3.

Fruits

achenes, usually trigonous or biconvex.

Achenes

trigonous.

Female scales

the lower longer than the perigynia; the upper reduced; more or less brown with paler midrib and margins, pointed to awned.

Carex geyeri

Cyperaceae

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Well-drained soils in dry, open, conifer forests, aspen stands, and openings, rarely in sagebrush, on both serpentine and nonserpentine substrates. 100–2500 m. BR, BW, Col, ECas, Lava, Owy, Sisk. CA, ID, NV, WA; north to southeastern British Columbia, east to CO, PA. Native.

Carex geyeri is a common ground cover in open forest, especially in northeastern Oregon, recognized by its tough, flat, evergreen leaves from dark, scaly rhizomes. Similar pinegrass, Calamagrostis rubescens, usually has hairy internodes and when in flower it is easily distinguished. Carex geyeri is important food for wildlife and livestock, especially in winter. In southwestern Oregon, C. geyeri can be confused with C. multicaulis, which is densely cespitose and has proportionately shorter, usually involute leaves, and longer, green, leaf-like, lower female scales.

Cosmopolitan. Approximately 100 genera; 16 genera treated in Flora.

Cyperaceae (except Eleocharis) is characterized by unusual holocentric chromosomes, in which spindle fibers attach throughout the length of the chromosome, not at discrete centromeres. Also, reduction of chromosome number occurs at the second division of meiosis. These traits are shared with the related family Juncaceae but not by other vascular plants. Chromosome numbers in sedges are often very high, but it is unclear if this represents polyploidy or fragmentation of holocentric chromosomes. When collecting sedges, get the rhizomes (if present) because some species are distinguished by their cespitose or rhizomatous growth form. If possible, collect extra inflorescences because checking floral traits can be destructive. In some genera, species identification requires mature fruits.

Source

Flora of Oregon, volume 1, page 202
Barbara Wilson, Richard Brainerd, Nick Otting

Flora of Oregon, volume 1, page 167

Sibling taxa