Flora of the Canadian Arctic Archipelago

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S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, L.J. Gillespie, A.K. Brysting, H. Solstad, and J.G. Harris

Poaceae Barnhart

French: Graminées,

Inuktitut: Iviit, ivisuka, ivitsuskaka.

Poaceae, Grass family.

Vegetative morphology. Plants 1–150 cm high (mean 26 cm); perennial herbs; caespitose, or not caespitose; not glandular viscid. Only fibrous roots present. Roots white, or yellow. Ground level or underground stems horizontal, or vertical, or absent; rhizomatous, or stoloniferous; elongate, or compact; 0.3–5 mm wide (mean 1.6 mm). Ground level or underground stems scales present; surfaces smooth, or striate, or grooved; 0.5–40 mm long (mean 16 mm); glabrous, or hairy. Aerial stems erect, or decumbent, or prostrate (rarely); not filiform. Leaves mainly basal, or distributed along the stems; alternate; distinctly distichous, or not distinctly distichous (usually); marcescent. Prophylls 0.4–30 mm long (mean 10); with smooth veins, or with scabrous veins, or with hairy veins; with pronounced keels, or lacking pronounced keels. Petioles absent. Sheaths present; persisting; forming a conspicuous build-up at the base of the plant; greyish brown; with the margins fused to the apex, or with the margins fused only in the lower part, or with the margins not fused; glabrous, or with trichomes; pubescent, or hirsute, or scabrous; sheath collars present. Ligules present; 0.1–12 mm long (mean 1.8 mm); membranous, or a fringed membrane; glabrous, or hairy; lanceolate, or ovate-oblong, or transversely oblong. Ligule apices acuminate, or acute, or obtuse, or truncate; entire, or erose, or lacerate, or cleft (higher on the sides). Leaf blades simple. Leaves grass-like. Blades 5–350 mm long, 0.2–9 mm wide (mean 1.7), appressed to the stem or spreading or reflexed, rolled in bud or folded in bud, linear, with sheath auricles or with clasping auricles or without auricles, flat or involute or folded, veins parallel, midvein conspicuously larger than the lateral veins or midvein similar in size to other veins in the leaf, bulliform cells in distinct rows on either side of the midvein or without bulliform cells in a distinct row on either side of the midvein, not septate nodulose. Blade adaxial surface glabrous or scabrous or hairy. Blade abaxial surface glabrous or scabrous or hairy. Blade margins entire, glabrous.

Reproductive morphology. Plants bisexual. Flowering stems circular or oval in cross section. Flowering stems about as high as the leaves, or conspicuously taller than the leaves; rooting at the lower nodes, or not rooting at the lower nodes; culm nodes not exposed, or becoming exposed; culm nodes number visible 1–3. Flag leaf sheaths inflated, or not inflated. Leaf or reduced bract subtending the base of the inflorescence without calloused tip. Inflorescences with bulbils, or without bulbils; spicate, or racemose, or paniculate; dense, or diffuse; linear, or oblong, or lanceolate, or ovate; 0.4–20 cm long (mean 5.4 mm); 2–125 mm wide (mean 22.7 mm). Inflorescences main axis glabrous, or scabrous, or hairy. Number of inflorescence branches at lowest node 0–8. Inflorescence primary branches 0.2–105 mm long (mean 17.6 mm); glabrous, or scabrous; with appressed secondary branches, or with spreading secondary branches. Pedicels present, or absent. Bisexual spike(s) without empty bracts at the base. Spikelets disarticulating above the glumes, or disarticulating at the base of the spikelet, or disarticulating at the nodes of the main axis; oblong to obovate; (1.5–)3–21 mm long (mean 6.3 mm); 0.5–9.2 mm wide (mean 2.5 mm). Florets per spikelet 0–10 (mean 3). Floral scales not reflexed; not falling early. Two glumes present. First glume 0.02–4.6 × the length of the second glume (mean 0.9 mm); 0.1–1.2 × spikelet length (mean 0.54); 0.05–17 mm long (mean 5); linear, or oblong, or lanceolate, or ovate, or oblanceolate; glabrous, or with trichomes; margins glabrous, or ciliate; veins 0, or 1, or 2, or 3, or 4, or 5; apex acuminate, or acute, or obtuse, or truncate. Second glume 0.4 × as long as the spikelet or less, or 0.4–0.9 × as long as the spikelet, or as long or longer than the spikelet; shorter than the lowest floret, or almost as long as, or longer than, the lowest floret; 0.3–150 mm long (mean 5.6 mm). Second glume linear, or oblong, or lanceolate, or ovate, or elliptic, or oblanceolate. Second glume glabrous, or with trichomes; veins 0, or 1, or 2, or 3, or 4, or 5, or 6. Rachilla pronounced between the florets, or not pronounced between the florets; terminating in a well-formed floret, or terminating in a vestigial floret, or extending beyond the uppermost floret; internode 1–2.2 mm long (mean 1.6 mm); internode 0.04–0.25 mm wide (mean 0.1 mm); internode glabrous, or scabrous, or hairy. Callus differentiated, or not differentiated; hairs 0–3.5 mm long (mean 0.67 mm); hairs shorter than the floret, or sub-equal to the floret (rarely). Lemma oblong, or ovate, or lanceolate, or elliptic, or obovate, or oblanceolate; 1.3–4.141–18.5 mm long; keeled, or rounded on the back; lemma not strongly inrolled, or lemma strongly inrolled; surface shiny, or dull; surface glabrous, or sparsely scabrous, or hairy; surface with trichomes on veins only, or on and between the veins; veins 1–7; apex acuminate, or acute, or rounded, or truncate; apex entire, or erose, or lacerate, or bifid; apex glabrous, or ciliate; awned, or awnless. Awn arising from the tip, or from below the apex but above the middle, or from the middle or below, or from just above the base. Awn 0–60 mm long (mean 3.8 mm). Palea well developed, or vestigial, or absent; 0.2–14 mm long (mean 3.6 mm); veins glabrous, or scabrous, or hairy. Flowers bilaterally symmetrical (zygomorphic); bisexual. Perianth represented by lodicules. Stamens 3; stamen filaments all equal in length; free of the corolla. Anthers 0.2–7 mm long (mean 1.6). Ovary superior; carpels 3; syncarpous. Styles 2; free. Placentation basal. Ovules per ovary 1. Fruit sessile; dry; a caryopsis; elongate-cylindrical; 0.9–10 mm long (mean 2.5 mm); glabrous; indehiscent. Styles persisting but not modified. Seeds 1.

Indigenous knowledge. Aqajait refers to very thin and soft grasses found in rivers or the seas which look like hair (Pleuropogon?). They could be used as a bandage for a cut on the hand (Ootoova et al. 2001). Ivik is the general name given to all grasses in the Central Arctic (Burt 2000).

Ecology and habitat. Substrates: rocks, gravel, sand, silt, clay, till, moss; with low organic content, with high organic content, peat; acidic, or calcareous, or halophytic, or nitrophilous.

General notes. Soreng and Davis (2000) presented the phylogenetic structure in Poaceae, subfamily Pooideae, as inferred from 601 chloroplast DNA restriction site characters and 67 morphological characters.

Illustrations. • Habitat with four species of Poa.


This publication is available on the internet (posted May 2011) and on CD-ROM (published in 2007). These versions are identical in content, except that the errata page for CD-ROM is accessible on the main index page of the web version.

Recommended citation for the web-based version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. NRC Research Press, National Research Council of Canada, Ottawa. http://nature.ca/aaflora/data, accessed on DATE.

Recommended citation for the CD-ROM version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. [CD-ROM] NRC Research Press, National Research Council of Canada, Ottawa.

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