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GRASSES
OF THE COLUMBIA BASIN OF BRITISH COLUMBIA
Although we have kept the Stipa in their traditional grouping, the genus Stipa has recently had some rearrangement. The species that are found in British Columbia have been moved to two genera. The long-awned Stipa are now called Hesperostipa and are differentiated by the sharp callus that is 1/5 or more the length of the flower and the awns that are 4-30 cm long. The non-long-awned native species have been moved to Achnatherum. The new key for the Stipaea adapted from Barkworth (1999) has Achnatherum separated from Piptatherum (Oryzopsis) by callus shape and length and flower shape. Achnatherum is separated from Hesperostipa by callus shape and length as well as awn length. Those species remaining in Stipa are introduced, cultivated species of which there are none in B.C. These changes have been part of Hickman (1993) and will be part of the Manual of Grasses (Barkworth).
Stipa species are important range grasses, but the sharp awns of some of the species may hurt grazing stock such as sheep.
Leaves and Stem: Erect somewhat leafy stems arise from a tuft of basal leaves. Sheaths are open and there are no auricles. The leaf blades are 1-2 mm wide and usually inrolled. The membranelike (or at least translucent) ligule is 3-5 mm long and has a rounded and split-to-torn margin. Flowerhead and Flowers: The flowerhead is somewhat narrow, reaching 7-20 cm long. The one-flowered spikelets are attached close to the central axis of the flowerhead. There are two, almost equal, narrow, persistent glumes, ranging from 15-25 (mostly 20) mm long. The lemmas are 8-12 mm long, hardened and are attached at the base to a sharp-pointed callus. The callus and the lemma are covered in stiff hairs, but the covering on the lemma surface is sparse. The long, slender awns twist many times from the tip of the lemma and bend once or more along their length. The awn tip is usually flexible. Awns may reach 15 cm long. Similar species: Needle-and-thread Grass can be confused with two other long-awned species in the Columbia Basin: Short-awned Porcupine Grass (S. curtiseta) and Porcupinegrass (S. spartea). The tips of the awns of Needle-and-thread Grass are usually flexible and curved, whereas those of the other two species tend to be straight. The lemmas of Needle-and-thread Grass have hairs over the entire surface, whereas those of the other species are more or less hairless or have hairs arranged in zones (lines) along the length of the lemma, leaving narrow strips or grooves hairless. The ligules of the lower and basal leaves are thin in Needle-and-thread Grass and thick and firmer in the other two species. Porcupinegrass is an uncommon Blue-listed species with 10-18-cm-long awns. Needle-and-thread Grass is called Hesperostipa comata in Hickman (1993).
Leaves and Stem: Erect somewhat-leafy stems arise from a tuft of basal leaves. Sheaths are open and there are no auricles. Flat to inrolled leaf blades are 2-5 mm wide. The stiff relatively thickened, relatively short ligule is 0.5-3 mm long and has a rounded and somewhat-hairy margin. Ligules of the lower and basal leaves tend to be short and thickened. Flowerhead and Flowers: The flowerhead is narrowed, reaching 10-20 cm long. The one-flowered spikelets are attached to branches held close to the central axis. There are two, narrow, almost equal glumes that are 2-3 cm long, and longer than the lemma (not including the awn). The lemmas are 7.5-11 mm long, hardened and attached at the base to a sharp-pointed callus. The callus is covered in stiff hairs. The lemma surface may be smooth or covered in hairs arranged in lengthwise strips or lines. Between the strips there are smooth areas or grooves. The slender awns twist many times from the tip of the lemma, and bend once or more along their length. The awn tip is usually straight. Awns range from 5-9 cm long. Similar species: See the description for Needle-and-thread Grass. Short-awned Porcupine Grass is separated from the very similar Porcupinegrass most easily on the basis of awn length. The awns of Short-awned Porcupine Grass are less than 10 cm long and the lemmas are also relatively short (7.5-10 mm). Both lemmas and awns of Porcupinegrass are longer. Porcupinegrass is an uncommon Blue-listed species found mainly around Castlegar; whereas Short-awned Porcupine Grass is more widespread based on the Royal BC Museum's Herbarium records. Hitchcock et al. (1969:717) consider this to be a somewhat-dwarfish phase of Porcupinegrass.
Leaves and Stem: Several stems arise from a tuft of 1-mm-wide long leaves. Sheaths are open and there are no auricles. The leaves are generally smooth and strongly inrolled. The smooth-edged to torn ligules are 6 mm long and easy to see. Flowerhead and Flowers: The wide, open flowerhead is 8-16 cm tall and has spikelets distributed at the tips of widely spread branches. Each spikelet has a single flower with rounded and pointed glumes that are 5-9 mm long and wrap around the flower. One glume is slightly longer than the other and exceeds the lemma -- which is 4-6 mm long -- but not its awn. An obvious mass of dense, long, white hairs covers the dark (reddish) oval lemma. A stout, 4-6-mm-long awn extends from the tip of the lemma. Similar Species: The rounded glumes in combination with long lemma hairs are unlike those of other Stipa species. The persistent awns and broad flowerhead differentiate Indian Ricegrass from Oryzopsis species.
Leaves and Stem: Open sheaths vary from smooth to densely hairy. There are no auricles. Inrolled to flattened leaf blades are 1-4 mm wide and 10-30 cm long. The ligules are 0.2-1.2 mm long and have a rounded to chopped off form. Flowerhead and Flowers: The narrowed flowerhead ranges from 9-30 cm long. Branches (as many as six at the lowest node) are straight and more or less pressed against the axis (appressed and ascending). The narrowed glumes are longer than the single flower. Of the two glumes, one is slightly longer than the other (6.4-10.5 mm long). The lemma is 4-6 mm long and covered in white hairs. Awns are 2-3 cm long and twice bent. The lowest segment of the awn is rough, but not covered in hairs. Similar Species: Columbian Needlegrass has a narrowed, somewhat-spikelike flowerhead compared to Spreading Needlegrass (Stipa richardsonii). The first two segments of the awns of Columbian Needlegrass have short hairs or are only rough, whereas those of Stiff Needlegrass (S. occidentalis) have 1-mm-long hairs. For more details on this species and its relationship to related species, consult Barkworth et al. (1979).
Leaves and Stem: Sheaths are open and smooth or hairy. There are no auricles. The leaves are 1-5 mm wide, stiff and usually inrolled. The ligule is about 0.5 mm long. Flowerhead and Flowers: The flowerhead is 8-20 cm long, narrow, spikelike and has protruding, bristly awns. The two nearly equal glumes are longer than the single flower. A 3-4-cm-long bent, twisted awn extends from the tip of the hairy lemma. The lowest two segments of the twice-bent awn are covered in hairs, making them look feathery. Similar species: Stiff Needlegrass has a narrowed to somewhat-spikelike flowerhead compared to Spreading Needlegrass. The first two segments of the awns of Stiff Needlegrass have 1-mm-ong hairs, whereas those of the similar Columbian Needlegrass have short hairs, or are only rough.
Leaves and Stem: Several stems rise from a tuft of basal leaves. Leaf sheaths are open and smooth to slightly hairy. There are no auricles. The leaf blades are 1.5-3.0 mm wide, usually folded to slightly inrolled and may feel a little rough. The ligules are 0.5 mm long and higher at the sides than at the middle. Flowerhead and Flowers: The sparse, open flowerhead ranges from 7-20 cm high. Its spreading branches often droop and have only a few single-flowered spikelets near the tips. The two narrow glumes (8-10 mm) are slightly longer than the first flower (not including the awn). One glume is noticeably shorter than the other. The lemma is 5-6 mm long and bears an 18-25-mm-long awn at the tip. The awn is twice bent, of which the first segment is hairy, the second segment less hairy and the last portion is only rough to the touch. Similar Species: Spreading Needlegrass has an open, spreading flowerhead with flexuous branches, whereas Stiff Needlegrass and Columbian Needlegrass have somewhat-spikelike flowerheads.
Leaves and Stem: Erect somewhat-leafy stems arise from a tuft of basal leaves. Sheaths are open and there are no auricles. Flat to inrolled leaf blades are 1-5 mm wide. The thickened ligule is 0.5-3 mm long and has a rounded and somewhat-hairy margin. Ligules of lower and basal leaves tend to be short and thickened. Flowerhead and Flowers: The flowerhead is somewhat narrowed, reaching 10-20 cm long. The one-flowered spikelets are attached close to the central axis. There are two glumes that are almost equal, 3-4 cm long, narrow and are much longer than the lemma (not including the awn). The lemmas are 12-16 mm long, hardened and are attached at the base to a sharp-pointed callus. The callus is covered in stiff hairs. The lemma surface may be smooth or covered in hairs arranged in zones or strips. Between the strips there are smooth zones or grooves. The slender awns twist many times from the tip of the lemma, and bend once or more along their length. The awn tip is usually straight. Awns range from 10-17 cm long. Similar Species: Porcupinegrass is most easily recognized by its extremely long, twisted awns. See Needle-and-thread Grass and Short-awned Porcupine Grass. Porcupinegrass is included by some authors in Hesperostipa.
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Habitat: Porcupinegrass grows in open, grassy habitats of
lower valley slopes. It is known from Castlegar in the Columbia
Basin region, but may occur at other scattered localities. Porcupinegrass
has not been recently collected in the Columbia Basin, and is Blue
Listed by the the B.C. Conservation Data Centre. There is no specimen
of it from the Columbia Basin in the Royal BC Museum's collection.