Festuca of North America


S. G. Aiken, M. J. Dallwitz, C. L. McJannet, and L. L. Consaul

Festuca subuliflora Scribn.



In Macoun Cat. Canad. Pl. Add. and Corr. I-IV 2(5): 396. 1890. Type: Canada. British Columbia: Vancouver Island, Goldstream, 29 June 1897, Macoun 7. Isotype: CAN!

F. ambigua Vasey, Contrib. U.S. Natl. Herb. 1: 277. 1893, non F. ambigua Le Gall, Fl. Morihan, 731. 1852. F. denticulata Beal, Grasses N. Am. 2: 589. 1896. Type: U.S.A. Oregon: in 1881, T.J. Howell 19. US!

Habit. Plants deep green (leaves mainly on the culms, leafy to near the panicle), (40–)60–100(–125) cm high, not densely tufted, tiller bases not stiffly erect, bases purplish or not purplish, horizontal rooting stems absent. Vegetative shoots arising outside, or breaking through the base of existing sheaths.

Vegetative morphology. Sheaths glabrous or with trichomes (copiously hirsute), not conspicuous at the base of the plant, splitting between the veins (towards the end of the growing season), open more than half their length (prophylls have scabrous keels, if present). Collars glabrous (usually, sometimes villous if abaxial leaf blade has long trichomes). Auricles absent. Ligules 0.2–0.6 mm long, ciliate (the cilia as long, or longer than the ligule membrane). Leaf blades (10–)15–30(–40) cm long, more or less lax. Adaxial blade surfaces glabrous or with trichomes (densely pubescent), abaxial blade surfaces glabrous or with trichomes. Leaf blades flat (to somewhat inrolled, strongly narrowed at the base), 2–6(–10) mm wide. Veins 15–30 (intercostal region about half the width of the veins). Adaxial to abaxial sclerenchyma strands present. Abaxial sclerenchyma in discrete, relatively narrow strands opposite the veins. Uppermost culm leaf sheaths not inflated. Flag leaf blades 5–15 cm long. Culm nodes becoming exposed, 2–4; internodes glabrous.

Floral morphology. Inflorescence (7–)10–20 cm long. Inflorescence branches at the lowest node 1 (rarely 2, pulvinate at the base), spreading (tending to droop), 3–15 cm long. Rachis rounded in cross section or angular in cross section, trichomes mainly on the ridges or trichomes over the entire surface. Spikelets loosely scattered in an open panicle with slender branches (spikelets towards the ends of the branches); (3–)6–11(–15) on the longest branches; 8–12.5 mm long, 1–5 mm wide. Proliferating spikelets absent (not recorded for this taxon). Florets (2–)3–4(–5). Glumes unequal (rarely approaching subequal), glabrous or with trichomes, vestiture at the apex only (scabrous on the midvein, scaberulous towards apex), margins ciliate (glumes tend to inroll and obscure the margins). First glume 2–4 mm long, veins 1. Second glume shorter than the first lemma, 3.5–5(–6) mm long, veins 1–3. Rachilla internodes antrorsely scabrous (segments 1.5–2.5 mm long). Lemma callus elongated with a tuft of stiff hairs at the base. Lemma 6–9 mm long, with 5 distinct veins in dorsal view, with trichomes (scabrous, particularly on the vein), trichomes over the entire surface; apex apically cleft. Lemma awn 10–15 mm long (crinkled, flexuous, often recurved). Palea 6.5–8.5 mm long, distinctly pubescent between the keels. Lodicules with marginal teeth, glabrous or ciliate, 0.8–1 mm long. Anthers 2.5–4 mm long. Ovary apex pubescent. Caryopsis 4–5 mm long.

Cytology. 2n = 28.

Habitat and Distribution. Native; alpine. Predominantly in woods, but also on moist slopes and in meadows, from near sea level to subalpine. Canada: B.C. (west of the Cascades); Northwestern USA: Oreg., Wash.; Southwestern USA: Calif.

Classification. Subg. Subulatae Tzvelev, sect. Subulatae Tzvelev (subg. Subuliflorae, (Alexeev 1980)).


"This species is closely related to F. elmeri Scribn. & Merr. which also has bifid, strongly veined lemmas and blades hairy on the ventral surface, but which differs in ligule character and in the non-jointed rachilla segments. The three species, F. subulata Trin., F. subuliflora, and F. elmeri, have many unusual features in common, but apparently are amply distinct," from Hitchcock et al. (1969). The distribution map of the species presented in Aiken et al. (1997). suggested that two of the species have limited west coast distributions. The analyses of this database suggested that the three species are more closely related than the species in sect. Obtusae.


• Line drawing. Illustrated in Piper (1906) as F. subuliflora. • Distribution map

The interactive key provides access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, and summaries of attributes within groups of taxa.

Cite this publication as: ‘Aiken, S.G., Dallwitz, M.J., McJannet, C.L. and Consaul, L.L. 1996 onwards. Festuca of North America: descriptions, illustrations, identification, and information retrieval. Version: 19th October 2005. http://delta-intkey.com’. Aiken, Dallwitz, McJannet, and Consaul (1997) should also be cited (see References).