Plant Species of San Jacinto Mountain: Key To High-Elevation Carex Species

1. Infl with 3-7 spikes with all bases clearly separate, not overlapping

2. Leaf blades (and perigynia) pubescent ... C. sartwelliana
2'. Leaf blades glabrous or scabrous on margins
3. Perigynia pubescent; spike 5-10 mm; pl low, matlike, infl often hidden amid lvs ... C. rossii
3'. Perigynia glabrous; spike 7-70 mm; pl tall, infl not hidden
4. Spikes 7-27 mm, 2-3.5(5) x longer than wide; terminal spikelet gen pistillate at tip, sometimes all staminate; lateral spikelets staminate at tip; stigmas 3 ... C. heteroneura
4'. Spikes 25-70 mm, longest 5-10 x longer than wide; infl with 1-3 terminal all male spikes, lower lateral spikelets all pistillate; stigmas 2 ... (5)
5. Plant glaucous, not cespitose ... C. nebrascensis
5'. Plant green, cespitose ... C. senta

1'. Infl with 4-35 spikes with some spike bases not clearly separate

6. Infl elongate, 2-5 x longer than wide
7. Distance between lowermost spikes >> 10 x spike lengths ... C. lemmonii
7'. Distance between lowermost spikes << 10 x spike lengths
8. Infl 3.5-5 x longer than wide, 2.5-8 cm long; spikes 7-35 ... C. fracta (and maybe the very similar C. mariposana if it exists here)
8'. Infl 1.2-4 x longer than wide; 1-3 cm long; spikes 4-11(14)
9. Infl 1.2-2.2 x longer than wide, 1-2 cm long; perigynium tip reddish or brown, beak entire; perigynium veins extended above fruit ... C. abrupta2
9'. Infl 1.5-4 x longer than wide, 1-3 cm long; perigynium tip not reddish, beak serrate; perigynium veins not extended above fruit ... C. subfusca

6'. Infl capitate, 1-2 x longer than wide

10. Infl with lowermost bracts leaf-like, >> spikes ... C. athrostachya
10'. Infl with all bracts < spikes except sometimes lowest
11. Spikes staminate at tip, perigynia spreading
12 Scales dark brown with inconspicuous midrib; perigynium margin entire, nerved on both faces, 3-4 mm long, with shallowly bidentate beak, wall filled with pithy tissue below .. C. jonesii
12' Scales light- to red-brown, midrib conspicuous, greenish, extreme margin white; perigynium margin serrulate above middle, only faintly veined on inner face, 3.5-5 mm long, with sharply bidentate beak, wall not filled with pithy tissue .. C. hoodii
11'. Spikes pistillate at tip; perigynia erect to ascending
13. +- Dry areas, including dryish meadows; spikes 10-12 mm; pistillate bracts longer than perigynia; beak to top of fruit 2-2.8(-3.3) mm ... C. multicostata
13'. Moist areas; spikes 4.4-10.8 mm; pistillate bracts shorter than perigynia; beak to top of fruit (1.6-)2-2.3 mm ... C. abrupta2
http://tchester.org/sj/species/carex_key_with_pix.html
Updated 8 November 2009.