Festuca of North America
| Festuca of North America | |
Nomenclature
Bull. Torrey Bot. Club 29: 468. 1902. Type: U.S.A. California: Santa Clara Co., Stanford University, April 1900, A.D.E. Elmer 2101. Holotype: US! Isotype: US.
Festuca jonesii var. conferta Hack. ex Beal, Grasses N. Am. 2: 593. 1896. Festuca elmeri subsp. luxurians Piper, Contrib. U.S. Natl. Herb. 10: 38. 1934. Festuca elmeri var. conferta (Hack.) Hitchc. Am. J. Bot. 21: 128. 1934. Type: U.S.A. California: San Jose Normal School, collector unknown. "The type of this name was in the herbarium of Professor Scribner, since destroyed by fire" (Piper 1906). Isotype: US!
Habit. Plants deep green (leaves mainly on the culms), 40–100 cm high, not densely tufted, tiller bases not stiffly erect (but not forming bunches), bases not purplish, horizontal rooting stems absent. Vegetative shoots arising outside, or breaking through the base of existing sheaths.
Vegetative morphology. Sheaths glabrous, 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. Collars glabrous. Auricles absent. Ligules 0.1–0.5 mm long, ciliate (cilia are shorter than the ligule membrane). Leaf blades 15–40 cm long, more or less lax. Adaxial blade surfaces with trichomes (scabrous or pubescent), abaxial blade surfaces glabrous. Leaf blades flat (sometimes loosely involute, veins prominent, similar to the leaves of F. subulata), 1.8–6 mm wide. Veins 8–18. 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, 3; internodes glabrous.
Floral morphology. Inflorescence 10–20 cm long (very pale green). Inflorescence branches at the lowest node 1–3, spreading, 7–12 cm long (slender, pulvinate at the base). Rachis 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; 8–13 on the longest branches; 7–10.5 mm long, (1–)1.5–3 mm wide. Proliferating spikelets absent (not recorded for this taxon). Florets 2–6. Glumes unequal, glabrous (or nearly so), margins ciliate. First glume 2–4 mm long, veins 1. Second glume shorter than the first lemma, 3–4.6 mm long, veins 3. Rachilla internodes antrorsely scabrous (approximately 1.5 mm long). Lemma callus not elongated. Lemma 5.5–7 mm long, with 5 distinct veins in dorsal view (usually), with trichomes (minutely hispidulous), trichomes over the entire surface; apex apically cleft. Lemma awn 2–5(–8) mm long. Palea 5.6–7.6 mm long (slightly longer than the lemma; the two scabrous keels meeting at an acuminate apex and sometimes purple), distinctly pubescent between the keels. Lodicules with marginal teeth, glabrous, 0.7–1 mm long. Anthers 3.4–4 mm long. Ovary apex pubescent. Caryopsis 2.5–3.5 mm long.
Cytology. 2n = unknown.
Habitat and Distribution. Native; forest and woodland. Northwestern USA: Oreg.; Southwestern USA: Calif.
Classification. Subg. Subulatae Tzvelev, sect. Subulatae Tzvelev (sect. Elmeri Scribn. & Merr. 1902. Bull. Torrey Bot. Club 29: 408, followed by Alexeev (1980)).
Notes
During the preparation of the treatment of Festuca for The Jepson Manual: Higher plants of California (Aiken 1993), no reasons for recognizing subspecific taxa in F. elmeri were found.
Alexeev (1980), as translated, indicated that F. elmeri has been assigned to this monotypic section and is endemic to the states of Oregon and California. It differs from other species of subg. Subulatae in having blades that are ribbed on top, short bidentate lemmas on the apices of which are awns that emerge between the bidentate apices, and longer anthers. Festuca elmeri is similar to F. subuliflora Scribn. in these characters... It can be assumed that the species F. elmeri emerged as a result of the hybridization of F. subulata Trin. and F. subuliflora and that it inherited the ribbed blades, the structure of the lemmae and the large anthers from the second parent and the structure of the callus from the first parent.
Aiken et al. (1997) in analyses of this database concluded that F. elmeri, F. subulata, and F. subuliflora are distinct, but closely related and possibly sister taxa.
Illustrations
• Line drawing. Illustration of F. elmeri from Piper (1906). • Isotype specimen of name in synonymy: NY. Isotype specimen of F. howellii, Hack. ex Beal Grasses N. Amer. 2: 591. 1896. Label reads, "F. howellii Hook. Oregon. T. Howell. 7/5/1887". NY. • 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).
