84 Rhodora . [APRIL 
third of the culm, somewhat bunched; the blades flat, the upper 
long-attenuate, 1.5-3 mm. wide, 12-25 mm. long, minutely rough on 
the edges; lower sheaths without blades light brown, sheaths over- 
lapping; ventral band hyaline, white or light-green. Heads ovoid, 
13-20 mm. long; spikes 3-5, closely aggregated, gynaecandrous, 8- 
11 mm. long, 4-8 mm. wide, rounded at base, rounded or somewhat 
pointed at apex. Bracts scale-like, with brown center and broad 
white hyaline margin, shorter than the head, the lowest frequently 
stiff and attenuated. Scales ovate, blunt, about as long and broad 
as the perigynia, chestnut-brown with white hyaline margin especially 
well marked in the staminate and lower pistillate scales. Perigynia 
hidden by the scales, ascending, dark brown at maturity, dull ob- 
securely nerved on both faces, winged, ovate, 4.5-5.25 mm. long, 2- 
2.25 mm. wide, broadest near the top of the achene, contracted at base, 
sessile, rather abruptly contracted into a flat winged bidentate beak 
serrulate to the tip; teeth erect.1 mm. long. Achenes oval, 2 mm. 
long, 1.2 mm. wide, light brown and dull at maturity, substipitate; 
style slender; stigmas 2. 
The above description is based on plants found growing abundantly 
in dry soil at an elevation of 3550 m., 200 m. above the timber 
line, on Mt. Arapahoe, Boulder County, Colorado. My number 
3227, preserved in my herbarium, is designated as the type. At the 
type-locality are found Carex albo-nigra Mack. and C. ellynoides 
Holm. 
CanEx subimpressa, spec. nov. “Carex impressa (Wright) Mac- 
kenzie X Carex lanuginosa, Michx.” Clokey, Torreya, vol. 16, no. 9, 
Sept., 1916. 
This hybrid has become so well established and shows such vigor, 
having become more abundant than either parent at the type locality, 
that it should be given rank as a species. My number 2338, pre- 
served in my herbarium, is designated as the type. 
^ 
CAREX TRIBULOIDES, Wahl. var. sangamonensis, var. nov. Grow- 
ing in small clumps from short stout rootstocks. Culms 2.2-6.5 dm. 
high, slender, soft, sharply angled, very slightly rough on the edges 
just below the head, about the length of the leaves of the fertile culms. 
Leaves on the fertile culm 4-8, on the sterile very numerous, 1.5-4 mm. 
wide, scattered, soft, flat, ribbon-like, gradually tapering to a delicate 
point, rough on the edges, those of the sterile culms frequently much 
longer than the fertile culms. Sheaths overlapping, lowest some- 
what fibrillose at base. Inflorescence erect or somewhat flexuous, 
2-4.2 cm. long; spikes 4-6. occasionally 3 or 7 and rarely 8, dull 
green or straw-color, sessile, obovoid, blunt, slightly to decidedly 
