Festuca of North America
MOUNTAIN ROUGH FESCUE, FOOTHILLS ROUGH FESCUE, BUFFALO BUNCHGRASS. The last common name refers to the fact that buffalo were fond of this grass.
Mem. N.Y. Bot. Gard. 1: 57. 1900. F. scabrella var. major Vasey, Contrib. U.S. Natl. Herb. 1: 278. 1893. F. altaica var. major (Vasey) Gleason, Phytologia 4: 21. 1952. Type: U.S.A. Washington: Spokane Co., common on prairies, 18 June 1884, Suksdorf 118. Holotype: US!
"F. doreana Looman", Looman & Best, Budd's Flora Canad. Pr. Prov., Agric. Canada Research Branch Publ. 1662: 128. 1979. pro syn.
Habit. Plants bluish gray green, (30–)40–90 cm high, densely tufted (in Montana it grows in tussocks 30–40(-60) cm in diameter), tiller bases stiffly erect, bases purplish, horizontal rooting stems present (rarely as short rhizomes) or absent. Vegetative shoots arising from within existing sheaths, or arising outside, or breaking through the base of existing sheaths.
Vegetative morphology. Sheaths glabrous or glabrescent, conspicuous at the base of the plant, persisting for more than 1 year, remaining entire, not conspicuously splitting between the veins, open more than half their length (prophylls 2–5.5 cm long with glabrescent trichomes on the veins occur among the sheaths; a prophyll, 5.5 cm long, was found on a collection from Alberta, CAN 215039). Collars glabrous. Auricles represented by distinct, erect, swellings (usually) or absent. Ligules 0.1–0.5 mm long, ciliate. Leaf blades 10–60 cm long, erect, stiffish. Adaxial blade surfaces with trichomes, abaxial blade surfaces with trichomes (illustrated Aiken and Lefkovitch 1984, p.1868 and in the image library). Leaf blades flat (rarely) or plicate (usually), 1.6–3 mm wide (when flat or loosely rolled); 0.6–0.95–1.75 mm wide, 0.8–1.02–1.9 mm deep. Veins 7–10. Adaxial to abaxial sclerenchyma strands present. Abaxial sclerenchyma well developed, in broad bands or continuous. Ribs 6–10 (prominent). Uppermost culm leaf sheaths not inflated. Flag leaf blades 2.5–7.5 cm long. Culm nodes never exposed; internodes glabrous, or scabrous-hirsute.
Floral morphology. Inflorescence 5–18 cm long. Inflorescence branches at the lowest node 1–3, spreading ("open to somewhat contracted at anthesis", Looman and Best 1979, p.128), 2.5–7(–13) cm long (tending to be stiffer than in F. altaica and not secund). Rachis rounded in cross section or angular in cross section, trichomes over the entire surface. Spikelets loosely scattered in an open panicle with slender branches (usually greenish); 2–6 on the longest branches; 8–12(–16) mm long, 2.5–7 mm wide. Proliferating spikelets absent. Florets (3–)4–5(–7). Glumes unequal (usually, but rarely approaching subequal), glabrous or with trichomes, vestiture at the apex only, margins ciliate (border less conspicuously translucent than in plants of F. altaica). First glume 4.5–7.5(–8.5) mm long, veins 1(–3). Second glume shorter than the first lemma, 5.3–8.2(–9) mm long, veins (1–)3. Rachilla internodes antrorsely scabrous. Lemma callus not elongated. Lemma (6.2–)7–8.5(–10) mm long, with 5 distinct veins in dorsal view or nerveless in dorsal view or sometimes with only the centre vein distinct, with trichomes, trichomes over the entire surface; apex entire (illustrated by Pavlick and Looman 1984, p. 1742 and in the image library; the Suksdorf 118 type specimen (US) has a limited number of florets, but several have dried with the veins of the lemma relatively prominent). Lemma awn 0.5–1.5 mm long. Palea 6–9 mm long, distinctly pubescent between the keels. Lodicules with marginal teeth, glabrous (rarely) or ciliate, 1–1.5 mm long. Anthers (3.3–)4.5–6 mm long. Ovary apex pubescent. Caryopsis 3.5–4.5 mm long.
Cytology. 2n = 56.
Habitat and Distribution. Native; rangeland, prairie, dry habitats. Canada: Alta., B.C.; Northwestern USA: Oreg., Wash.; Rocky Mountains USA: Idaho, Mont. (Harms (1985) suggested that Michigan and eastern Canadian disjunct populations of rough fescue belonged to this taxon, but after examining specimens we have mapped them as F. altaica).
Classification. Subg. Leucopoa (Griseb.) Hack. (subg. Hesperochloa, sect. Breviaristatae Krivot, Alexeev (1980) by implication).
Mountain fescue was placed in synonymy with F. altaica subsp. altaica Trin. by Piper (1906) and St.-Yves (1925). Alexeev (1985) placed mountain fescue into synonymy with F. hallii (Vasey) Piper. Harms (1985) gave reasons why the taxon should be treated as a subspecies, F. altaica subsp. scabrella (Torrey) Hultén, but based the name on a type specimen that is considered, by S. G. Aiken, to be F. altaica Trin. (see below). It was considered to be a species, F. campestris, by Pavlick and Looman (1984), Aiken and Lefkovitch (1984) and Aiken and Darbyshire (1990).
The map presented in Aiken and Lefkovitch (1984) and the more detailed maps in Aiken and Consaul (1995) indicate geographic separation among the taxa. Even where maps show the taxa as sympatric, e.g. southern Alberta and British Columbia, the plants are growing at different altitudes, separated by a band of boreal forest; F. altaica at tree line or above, F. campestris in grassland areas around 1500 m or below.
Aiken and Lefkovitch (1984) decided the results of an epidermal peel study supported the Looman and Best (1979) concept of three species among the rough fescues occurring in Canada. However, they cautioned that the only measurement found to have potential for separating the taxa, namely the length of the intercostal cells, "fails to be useful for identification purposes as the ranges of values overlap among the species".
An SDS-PAGE study of seed proteins in the genus suggested that the three taxa F. altaica, F. campestris, and F. hallii appear to be closely related (Aiken and Gardiner 1991). The greater number of bands in the seed protein profiles recorded for F. campestris when compared with those for F. altaica and F. hallii indicated that this taxon is not an autoploid of either of them. The possibility that F. campestris is an allopolyploid of F. altaica × F. hallii was considered but could neither be proved nor disproved.
Leaf morphology is phenotypically plastic and many factors appear to result in reduced numbers of sclerenchyma strands, for example, when the leaves (a) have developed early in the growing season, (b) are relatively long, (c) come from a plant that has grown at high altitudes, (d) have regrown from tussocks that have been burnt or, (e) been severely grazed. This is shown in specimens towards the southern end of the distribution range and well documented in a US collection of specimens from Eastern Washington and Northern Montana. These specimens sometimes have leaves that are similar to those of F. hallii, but inflorescences and spikelets of F. campestris. The presence of B chromosomes appears to influence leaf width in F. altaica (Aiken and Fedak 1992) but whether B chromosomes occur in F. campestris has not been established.
The impact of grazing on vegetative morphology was suspected by C.V. Piper (Piper 1906) who wrote on a specimen, "Don't believe this indicates 'blades deciduous from the sheath with age', but that this plant was grazed (underlined twice). The junction of the sheath and blade may be found in the old plant." (Specimen: Washington: Kittitas Co., Wenstcha Mountains, 4000 ft, 2 July 1897, A.D. Elmer, 460. US 73432). The basal tussock of this specimen has the chewed remains of approximately 15 groups of sheaths that would usually have more than 45 leaves, by July, but has only 14 leaves developing from four of the sheath groups. Etiolation, leading to longer than usual leaves also appears to reduce the number of adaxial to abaxial sclerenchyma strands. (Specimen: Washington: Stepton, May 1900, J.R. Vasey 5. US 1005085, a sample with leaves, to 70 cm long and leaf cross sections with only 3 abaxial to adaxial sclerenchyma girders). This is consistent with findings in Aiken and Consaul (1995) that longer leaves in some Festuca species tend to become narrower and have less sclerenchyma. Burning may lead to new growth with narrow leaves. (Specimen: Montana: Sanders Co., 5 miles east of Thompson Falls, 21 April, 1934, C. L. Hitchcock. US 1730096). The variation observed in leaf anatomy characteristics suggests why Alexeev (1985) in a paper that illustrated leaf cross sections, recognized only F. altaica and F. hallii. In the course of this study, the taxonomic status of mountain fescue has been reconsidered and examined in analyses run on this database (see Aiken et al. 1997).
Characteristics found useful for separating the species follow.
1. The degree of rhizome development. Rhizomes are rarely observed in F. altaica, they are short, if present, in F. campestris (Johnston and Cosby, 1966) and well developed in F. hallii.
2. Colour differences of the inflorescences. Inflorescences are bluish gray green in F. campestris and purplish, or dark purple in F. altaica. (There is an albino form, F. altaica forma pallida Jordal).
3. The orientation of inflorescence branches. In F. altaica these are often blown to one side and slightly drooping, those of F. campestris are stiffer and even slightly ascending.
4. Relative lengths of glumes. The glumes of both species, F. altiaca and F. campestris, may approach subequal in length but they are usually conspicuously unequal. Also, the upper glume is consistently shorter than the adjacent lemma. These characters contrast with the character states in F. hallii spikelets, where the glumes are usually subequal and the upper glume is as long, or longer than the adjacent lemma.
5. The width and translucency of the glumes and lemma margins. In F. altaica these structures have conspicuously translucent borders causing the spikelets to shine in sunlight, those of F. campestris have less conspicuously transparent margins and the spikelets are not obviously shiny.
Harms (1985) discussed type specimens of the name F. scabrella Torrey, that were collected by Thomas Drummond "in alpine districts of the Rocky Mountains" in 1825 or 1826 on the John Franklin Second Expedition. Harms (1985) concluded that "unfortunately the quality of the type materials was too inadequate and the spikelets too immature to assure their unequivocal identification as either F. altaica sensu stricta or the more southern mountain taxon... Most of the individual plants appear depauperate for either taxon and have rather scanty panicles. Although measurements of the lengths of spikelets, glumes and lemmas fell more into the expected range for F. altaica sensu stricta than for the more southern mountain taxon, these are questionably reliable for the particular maturation stages. Coloration of herbage and spikelets was obscure. The rather contracted panicles with mostly ascending-erect upper branches, on the other hand, suggested the latter, as did the relatively inconspicuous glume-borders. Thus, identification of the available type material seemed inconclusive, although I was most inclined to place it with the more southern mountain taxon...."
In examining the isotype and possible second isotype collections of Drummond from GH, in 1994, (illustrated in the image library) the first author agreed with the annotations made by L.E. Pavlick (Sept. 1981) that these specimens are plants of F. altaica sensu stricta. They are similar to many that she has seen growing below 1000 m in the Northern Yukon. The culms are 28 cm to more than 50 cm high (one long culm has been cut and was obviously longer). One specimen has a flag leaf blade that has dried almost flat and is more than 2 mm wide. The specimens were collected as the inflorescences approached anthesis and the panicles can be described as immature but approaching open and lax; one of the branches has opened up to be at right angles to the main rachis. Spikelets are 10–13 mm long, with 3–5 florets. Most of the colour of the specimens has turned to a dark straw yellow, but the spikelets retain evidence of dark bands of purplish-brown on the lemmas. Some lemmas have conspicuous, translucent borders: on others the borders have inrolled somewhat, as the specimens dried. The lemma lengths range from 7–9.5 mm and rachilla internodes from 1.5–2 mm, making the florets of the spikelet more widely separated than is common in mountain fescue.
Since he was convinced that the Drummond specimens are more likely plants of mountain fescue, Harms (1985) placed the name F. scabrella var. major Vasey into synonymy. The type for this name, Suksdorf 118 has a pressed culm approximately 95 cm long, the leaves, although faded to straw colour, are slightly greyish green, the flag leaf blades are involute. The post-anthesis inflorescence branches are erect and up to 13 cm long, with numerous pairs of unequal glumes: the lower glumes 5–6(-6.5) mm long, the upper glumes 6.5–7(-8) mm long. A leaf cross section had five sclerenchyma girders and anatomy typical of mountain fescue. Rydberg (1900) based the species name F. campestris on the Suksdoff 118 specimen.
Buffalo bunchgrass produces a large amount of forage and is especially relished by horses and cattle; it is somewhat too hard a grass for sheep. On winter ranges, it is considered one of the best grasses, as it cures well on the stalk and retains its nutritive properties all winter. On the lower ranges, the small amount of snow held against the strong winds in the centre of the grass bunches serves both to moisten and soften the herbage, and is a source of water for the livestock. On the higher ranges, continuously covered by winter snow, this grass greens up faster in the spring and appears to be better relished by livestock than when growing on the lower winter ranges. The high palatability of both the leaves and stalks in many instances has resulted in cropping to the ground line which decreases the abundance of this valuable grass (Dayton 1931).
• Close up of flowering plants. Grasses in Festuca grassland in British Columbia. The taller grass is F. campestris. The marker, in 10 cm units, is beside a blue green plant of F. idahoensis. • Habitat. Tussock of F. campestris showing spring re-growth after burning (white arrows point to burned areas). Photographed in British Columbia by S.J. Darbyshire, 1982. • F. campestris beside F. idahoensis. The taller grass is F. campestris. The grass beside the marker, divided in to 10 cm units, is F. idahoensis. • Habitat in British Columbia. Fescue grasslands in British Columbia. F. campestris is a dominant grass, but there are some F. idahoensis plants, approaching the northern limit of its known range. • Grasslands in British Columbia. Grasslands in British Columbia. South facing, exposed slopes are too dry to support the growth of gymnosperm trees that occur on the north facing slopes. Shown in the foreground are planted, introduced Elymus species, which are usually found in a middle ground, native Festuca grassland. • Leaf anatomy. Leaf cross section of F. campestris. Plicate leaf blades are 0.6–0.95–1.75 mm wide and 0.8–1.02–1.9 mm deep, with 7–10 veins. Adaxial to abaxial sclerenchyma strands are present. Abaxial sclerenchyma strands are well developed, in broad bands or continuous. There are 6–10 prominent ribs. • Isotype specimen: NY. Isotype specimen of Festuca scabrella var. major, collected by W.N. Suksdorf Washington Ter., Spokane Co., W.N. Suksdorf, 118. • Specimen of interest: NY. Specimen of Festuca scabrella var. major, collected by W.N. Suksdorf Washington State, Spokane Co., prairies. June 18, 1881. This is a possible isotype, but lacks the collection number 188 on the label. • Holotype specimen: US. Type specimen of F. campestris. Left, label reads, "From the United States National Herbarium F. scabrella Trin. var. Locality: Spokane, Wash. Ter. Collector W.W. Suksdorf 118, June, 1884." US. • Cited with type specimen: US. Type specimen of F. campestris. Label reads," F. scabrella Torr. var. major V. Collector G.R. Vasey, Washington Territory, 1883. Cited in original description". US 1005099. • Impact of burning. Herbarium specimen of F. campestris. Plant less than 30 cm tall on 3 June 1902 show limited new seasons growth after burning. Leaf cross sections show fewer than 5 abaxial to adaxial sclerenchyma strands. For further discussion see the taxonomic notes. Eastern Washington: Wenar David Griffiths and J.S. Cotton 92. US 1005087. • 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).