Family: Poaceae |
Jerrold I. Davis and Laurie L. Consaul Plants annual, biennial, or perennial; usually cespitose, sometimes weakly or strongly stoloniferous and mat-forming. Culms 2–100 cm, erect or decumbent, sometimes geniculate; internodes hollow. Sheaths open to the base or nearly so; auricles absent; ligules membranous, acute to truncate, entire or erose; blades flat, folded, or involute. Inflorescences terminal panicles, open to contracted; branches smooth or scabrous, some branches longer than 1 cm; pedicels usually longer than 3 mm, thinner than 0.5 mm. Spikeletspedicellate, subterete to weakly laterally compressed, with 2–10 florets; disarticulation above the glumes, beneath the florets. Glumes usually unequal, sometimes subequal to equal, usually distinctly shorter than the lowest lemma in the spikelets, sometimes only slightly shorter, rarely longer, membranous, rounded or weakly keeled, veins obscure or prominent, apices unawned; lower glumes 1(3)-veined; upper glumes(1)3(5)-veined; calluses blunt, glabrous or pubescent; lemmas membranous to slightly or distinctly coriaceous, glabrous or pubescent, pubescence sometimes restricted to the bases of the veins, rounded or weakly keeled, at least distally, (3)5(7)-veined, veins obscure to prominent, more or less parallel distally, usually not extending to the apices, lateral veins sometimes reduced, apical margins with or without scabrules, apices usually acute to truncate, sometimes acuminate, entire or serrate to erose, unawned; paleassubequal to the lemmas, scarious or membranous distally, 2-veined, veins terminating at or beyond midlength; lodicules 2, free, glabrous; anthers 3; ovaries glabrous. Caryopses shorter than the lemmas, concealed at maturity, oblong, terete to dorsally flattened, falling free or with the palea or both the lemma and palea attached; hila oblong, about 1/3 or less the length of the caryopses. x = 7. Named for Benedetto Puccinelli (1808–1850), an Italian botanist. Puccinellia, a genus of approximately 120 species, is most abundant in the middle and high latitudes of the Northern Hemisphere. There are 21 species in the Flora region, of which 3 are introduced. Ten are confined to the arctic, four are circumarctic and two are transberingian. Most species of Puccinellia are halophytes, either in coastal habitats or in saline or otherwise mineralized soils of interior habitats. Polyploidy, selfing, and hybridization are widespread in the genus, and many of the species boundaries are controversial. Several of the species with Arctic distributions have received different taxonomic treatments in North America and Eurasia. The angle of the panicle branches (whether erect, ascending, etc.) refers to their position when the caryopses are mature. Lemma measurements should be made on the lowest lemma in the spikelets. Principal features of the lemmas, as used in the key and descriptions, are as follows. Scabrules (short, pointed hairs, similar in form to those that occur on the pedicels and inflorescence branches of many species of Puccinellia, and generally requiring magnification to observe) often occur along the distal margins of the lemmas. When present, they may be few and irregularly scattered, with gaps between them that are either wider than the individual scabrules (e.g., in some P. pumila), or arranged in a continuous palisade-like row that lacks gaps (e.g., in P. distans). Independent of the presence or absence of scabrules, the lemma margins may be entire (e.g., in P. pumila and P. distans) or serrate to erose (e.g., in P. andersonii, and P. vahliana). SELECTED REFERENCES Argus, G.W. and K.M. Pryer. 1990. Rare Vascular Plants in Canada: Our Natural Heritage. Canadian Museum of Nature, Ottawa, Ontario, Canada. 191 pp.; Consaul, L.L. and L.J. Gillespie. 2001. A re-evaluation of species limits in Canadian Arctic island Puccinellia (Poaceae): Resolving key characters. Canad. J. Bot. 79:927–956; Consaul, L.L., L.J. Gillespie, and K.I. MacInnes. 2005. Addition to the flora of Canada? A specimen from the Arctic Archipelago, Northwest Territories links two allopatric species of alkali grass. Canadian Field Naturalist 119: 497–506; Consaul, L.L., L.J. Gillespie, and M.J. Waterway. 2008a. Systematics of North American Arctic Diploid Puccinellia (Poaceae): Morphology, DNA Content, and AFLP Markers. Systematic Botany, 33(2):251-261 (2008), https://doi.org/10.1600/036364408784571662; Consaul, L.L., L.J. Gillespie, and M.J. Waterway. 2008b. Evolution and polyploid origins in North American Arctic Puccinellia (Poaceae) based on nuclear ribosomal spacer and chloroplast DNA sequences. Amer. J. Bot. 97( 324-326. https://doi.org/10.3732/ajb.0900180 Davis, J.I. 1983. Phenotypic plasticity and the selection of taxonomic characters in Puccinellia (Poaceae). Syst. Bot. 8:341–353; Fernald, M.L. and G.A. Weatherby. 1916. The genus Puccinellia in eastern North America. Rhodora 18:1–23; Porsild, A.E. 1964. Illustrated Flora of the Canadian Arctic Archipelago, ed. 2, rev. Bulletin of the National Museum of Canada No. 146 [Biological Series No. 50]. R. Duhamel, Queen’s Printer, Ottawa, Ontario, Canada. 218 pp.; Scribner, F.L. and E.D. Merrill. 1910. The grasses of Alaska. Contr. U.S. Natl. Herb. 133:47–92; Sørensen, T.J. 1953. A revision of the Greenland species of Puccinellia Parl. with contributions to our knowledge of the arctic Puccinellia flora in general. Meddel. Grønl. 136:1–169; Sørensen, T.J. 1955. Puccinellia agrostidea, Puccinellia bruggemannii, Puccinellia poacea. Pp. 78–82 in A.E. Porsild. The Vascular Plants of the Western Canadian Arctic Archipelago. Bulletin of the National Museum of Canada No. 135 [Biological Series No. 45]. E. Cloutier, Queen’s Printer, Ottawa, Ontario, Canada. 226 pp.; Swallen, J.R. 1944. The Alaskan species of Puccinellia. J. Wash. Acad. Sci. 34:16–32;Tsvelev, N.N. 1995. Puccinellia. Pp. 237–263 in J.G. Packer (ed., English edition). Flora of the Russian Arctic, vol. 1, trans. G.C.D. Griffiths. University of Alberta Press, Edmonton, Alberta, Canada. 330 pp. [English translation of A.I. Tolmachev (ed.). 1964. Arkticheskaya FloraSSSR, vol. 2. Nauka, Leningrad [St. Petersburg], Russia. 272 pp.] |