Spartina gracilis Trin.

Saarela, Jeffery M., 2012, Taxonomic synopsis of invasive and native Spartina (Poaceae, Chloridoideae) in the Pacific Northwest (British Columbia, Washington and Oregon), including the first report of Spartina xtownsendii for British Columbia, Canada, PhytoKeys 10, pp. 25-82 : 42

Spartina gracilis Trin.

Spartina gracilis Trin., Mém. Acad. Imp. Sci. Saint-Pétersbourg, Sér. 6, Sci. Math., Seconde Pt. Sci. Nat. 6,4(1-2): 110. 1845. Type. CANADA.Amer. bor., Hooker s.n. (isotypes: LE [LETRIN2058.01!], US [US92014!] (fragm. ex LE)).

Description:

See Mobberley (1956), Barkworth (2003), and Douglas et al. (2001). 2 n = 40 ( Marchant 1968b, Reeder 1977).

Common name.

Alkali cordgrass, big cordgrass.

Illustrations.

Hitchcock 1935:493, Hitchcock 1951: 513, Hitchcock et al. 1969:706, Barkworth 2003:251, Douglas et al. 2001:269.

Etymology.

The Latin epithet gracilis means "thin, slender" ( Stearn 1992), probably given in reference to the general habit of the species.

Distribution.

Southern Northwest Territories, Canada, to central Mexico ( Barkworth 2003). In the Pacific Northwest Spartina gracilis is distributed in the steppe and montane zones of the south central and south eastern parts of British Columbia ( Douglas et al. 2001), and in eastern Oregon and Washington ( Barkworth 2003, Wilson et al. 2012). It is not a salt marsh species and is not invasive.

Morphology.

Spartina gracilis is a distinctive taxon ( Fig. 8 ). In the Pacific Northwest it is likely to be most readily confused with Spartina pectinata , which also grows inland. It is distinguished from Spartina pectinata by the following combination of characters: upper glumes unawned or short-awned, awns to 2 mm long [vs. distinctly awned upper glumes, awns 3-8 mm long], ciliate glume keels [vs. pectinate glume keels], spikelets 6-11 mm long [vs. 10-25 mm long], ligules 0.5-1 mm long [vs. 1-3 mm long], 3-12 branches per inflorescence [vs. 5-50 branches per inflorescence], and 10-30 spikelets per branch [vs. 10-80 spikelets per branch]. It is distinguished from Spartina patens by its ciliate glume keels [vs. scabrous glume keels], inconspicuous lateral veins on the upper glumes [vs. conspicuous lateral veins on the upper glumes], most branches 3-6 mm wide [vs. most branches 2-3 mm wide], branches closely appressed to the main axis [vs. branches appressed, ascending or spreading from main axis], and florets more or less equaling the upper glumes in length [vs. florets shorter than the upper glumes]. Spartina gracilis can be readily separated from Spartina alterniflora , Spartina anglica and Spartina xtownsendii by its scabrous leaf margins [vs. glabrous leaf margins], and from Spartina densiflora by its rhizomatous habit [vs. cespitose].

Specimens examined.

CANADA. British Columbia: 23 mi W of Kamloops, 50.6667°N, 120.8569°W uncertainty 33215 m, 23 July 1941, W.A.Weber 2548 (CAN [CAN33940]); Thompson River valley between Spences Bridge and Cache Creek, 50.6059°N, 121.3386°W uncertainty 22 km, 15 July 1964, H.J.Scoggan 15626 (CAN [CAN308046], Fig. 8 ); Flying U Ranch, Cariboo, bank at edge of Green Lake, 51.4172°N, 121.2025°W uncertainty 8569 m, 21 June 1944, J.W.Eastham 11509 (CAN [CAN33941]); N of Kamloops, 50.6667°N, 120.3333°W uncertainty 7196 m, 13 Jun 1889, J.Macoun s.n. (CAN [CAN33943, Suppl. Fig. 26]); Kamloops, 50.6667°N, 120.3333°W uncertainty 7196 m, 4-7 Sep 1931, V.Kujala & A.Cajander s.n. (CAN [CAN394081, CAN394014, Suppl. Fig. 27]); 119 mile, Cariboo, 1 8 Jun 1942, J.A.Munro 23 (CAN [CAN33942]); Similkameen River, 10 Jun 1905, J.M.Macoun 77227 (CAN [CAN33944, Suppl. Fig. 28]). UNITED STATES OF AMERICA. Montana: Hound Creek, 30 Jul 1883, F. Lamson-Scribner 329 (CAN [CAN162196]). North Dakota: Ward County, 26 Jul 1963, L.F.Lautenschlager 694 (CAN [CAN297003]). Utah: Death Ridge-Horse Mountain Road, near Caanan Peak, 6800 ft, 15 June 1990, M.A.Franklin & D.Atwood 7129 (CAN[CAN563733]). Washington: Okanogan Co.: Loomiston, Aug 1897, A.D.E.Elmer 891 (CAN [CAN162194, CAN162191]).

Figures

Figure 8. Photograph of a specimen of Spartina gracilis collected in the Thompson River Valley, British Columbia (Scoggan 15626, CAN).