Spartina anglica C.E. Hubb., Bot. J. Linn. Soc. 76(4): 364. 1978.

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 : 36-39

Spartina anglica C.E. Hubb., Bot. J. Linn. Soc. 76(4): 364. 1978.

Spartina townsendii var. anglica (C.E. Hubb.) Lambinon & Maquet, Nouv. Fl. Belgique, Luxembourg, N. France (ed. 3) 923: 1983. Type. United Kingdom. West Sussex: Bosham, fruiging shore on mud-flats and muddy shingle, extending into water of Chichester Harbour, forming extensive masses, 17 Aug 1968, C.E.Hubbard S.17868A, sheet II (lectotype:K [K000710270!], here designated; isotypes: K [K000710269!], L [L100190!], US[US2907471!]). Note:The collection designated as the holotype by Hubbard (1978), Hubbard S.17868A, is mounted on two sheets at K: K000710269 and K000710270. The latter is clearly labeled 'sheet II’, but the former is not reciprocally cross-labeled as 'sheet I’ therefore the two sheets are duplicates according to the Code. The specimen indicated as 'sheet II" is more robust, and is here designated as the lectotype.

Description.

Culms 32-104 cm tall, thick, fleshy,rhizomatous, forming clumps and dense swards. Sheaths glabrous, occasionally with short, scattered hairs, when present hairs to 0.2 mm long; ligules 1-3 mm long; blades 6-45 cm long × 4-10 mm wide, flat proximally, moderately to strongly involute distally, divergent 30-60° from culms, adaxial surfaces glabrous, occasionally sparsely pubescent proximally, when present hairs to 0.2 mm long, abaxial surfaces glabrous, occasionally sparsely pubescent proximally, when present hairs to 0.5 mm long, margins smooth. Inflorescences 12-21.5(-31.5) cm long × 7-25 mm wide at midpoint, erect, with (2)3-5(-11) branches; branches (7-)8-15(-20) cm long × (3-)4-5(-6) mm wide, appressed to main axis or ascending; rachises 1-2.2 mm wide between spikelets, extending 2-20 mm beyond the distal spikelet, glabrous, margins glabrous, occasionally sparsely pubescent, when present the hairs 0.2-0.4 mm long. Spikelets (15-)16.5-25 mm long × 1.8-2.5(-2.8) mm wide, weakly appressed, weakly overlapping, calluses (1.5-)2-4.5 mm long. Glumes (weakly) moderately or densely pubescent, hairs 0.1-0.3 mm long, hairs usually denser and to 0.6 mm long proximally; keels scabrous or ciliate, hairs to 0.5 mm long; lower glumes 8-14 mm long × 0.5-0.7 mm wide, 1-veined, tips acute or obtuse; upper glumes 13-22 mm long × 1-1.5 mm wide, 3-6 veined, tips obtuse or acute; lemmas 11-17 mm long, 1-3-veined, appressed pubescent distally, glabrous proximally, margins membranous; paleas exceeding lemmas by 1-2 mm; anthers 7-10 mm long, yellowish, usually fully exserted at maturity, dehiscent, pollen fertile. 2 n = 120, 122, 124 ( Marchant 1963, 1968b).

Common name.

English cordgrass; common cordgrass.

Etymology.

The Latin epithet anglica means English, given to the species in reference to England, its place of origin.

Illustrations.

Barkworth 2003:248, Cope and Gray 2009:551.

Distribution.

Britain, China ( An et al. 2007, Bixing and Phillips 2006), Australia (Tasmania, Victoria, Kriwoken and Hedge 2000), New Zealand ( Partridge 1987), France (western coastal Brittany, Baumel et al. 2001), United States of America (Washington, California), and Canada (British Columbia).

Comments.

Spartina anglica is an amphidiploid taxon that arose in Britain in the 18th century from chromosome doubling of the sterile F1 hybrid taxon Spartina xtownsendii (see the discussion under that species for details, and reviews in Marchant 1968 and Gray et al. 1991). The origin of Spartina anglica is a remarkable and well-studied example of allopolyploid evolution.

Spartina anglica is a problematic invasive species in coastal areas of western North America, and has been present on the continent for over fifty years. In the United States it is known from Washington and California. It was planted in Puget Sound, Washington in 1961 ( Spicher and Josselyn 1985, Frenkel 1987) to provide forage for cattle and to stabilize a dike system ( Hacker et al. 2001). By 1997, it had expanded substantially in Puget Sound, occurring in 73 sites and covering 397 solid hectares of intertidal habitat ( Hacker et al. 2001, see Hedge et al. 2003). Eradication efforts in this region began in 1997 ( Hacker et al. 2001). In 1977 Spartina anglica was deliberately transplanted from Puget Sound to California where it was introduced at Creekside Park Marsh in San Francisco Bay, Marin County ( Spicher and Josselyn 1985), and it persists at this single location in the state (e.g., Grijalva et al. 2006, San Francisco Estuary Invasive Spartina Project 2012). Spartina anglica is mentioned, but not treated in Baird and Thieret (2012).

Spartina anglica was discovered in British Columbia in 2003 on Roberts Banks in the Fraser River estuary and in Boundary Bay along the British Columbia and Washington border ( Williams 2004). Williams (2004) noted the infestation to be in its early stages in 2003, and estimated the species to have arrived in the area some three to five years earlier. Additional collections were made in 2004 in Boundary Bay (Lim s.n., V-two specimens) and on Roberts Banks ( Williams 2004 -1, 2004-2 [ Fig. 3 ], 2004-3). Following this initial documentation of Spartina anglica in British Columbia, extensive field surveys and mapping exercises were undertaken to determine the extent of the species at Roberts Bank and in Boundary Bay, and an eradication plan was implemented (Dresen et al. 2010; Williams et al. 2010). Despite removal and eradication efforts, by 2009 Spartina anglica had increased dramatically in these regions ( Ducks Unlimited Canada 2010). It is currently reproducing by seed production and vegetatively by outward clonal growth forming meadows and by drifting plant parts (R. Knight, personal communication 2010). There are only a few herbarium collections documenting Spartina anglica in the province, collected by G. Williams and P. Lim when the taxon was first found. Additional collections should be made at these and other sites where the species is found, to properly document its continued existence and spread.

Morphology.

The description here is based on collections from Washington, Oregon, and British Columbia, and Old World material housed at CAN and UBC (see Specimens Examined). Spartina anglica is morphologically similar to Spartina xtownsendii , and the two can be challenging to distinguish. Differences between these species were characterized in detail by Marchant (1968a), and my observations here are in general accordance with his findings. Mobberley (1956) commented only briefly on their differences in his treatment of Spartina xtownsendii , the name under which both ploidal forms of the taxon were recognized at the time. Only a few taxonomic keys in North America include both taxa ( Barkworth 2003, Kozloff 2005), emphasizing variation in ligule length, anther length, and anther dehiscence for identification. In addition to these characters, the key presented here includes spikelet length, upper glume venation, and upper glume length.

Overall, plants of Spartina anglica tend to be larger than those of Spartina xtownsendii , including the lengths of reproductive structures useful in distinguishing the taxa. The species can be distinguished with careful measurements on herbarium specimens, though there is some overlap in the diagnostic morphological characteristics. When making a determination, multiple characters should be examined and multiple measurements should be made on a single plant when possible. Spartina anglica is distinguished from Spartina xtownsendii by its longer spikelets [(15-)16.5-25 mm long vs. 14-17.5 mm long]; longer anthers [7-10 mm long vs. 5-7(-8.5) mm long]; anthers that are fully exserted and dehiscent [vs. anthers that are not or incompletely exserted and indehiscent; Fig. 4 ]; fertile pollen [vs. sterile pollen (see below and Fig. 5 )]; longer ligules [1-3 mm long vs. 1-1.5 mm long]; 3-6-veined upper glumes [vs. 3-veined upper glumes]; and longer upper glumes [13-22 mm long vs. 12.5-16.5 mm long]. Marchant (1968a) observed that leaf blade angle with respect to the culm can be used to differentiate the taxa, as the blades tend to be more erect in Spartina xtownsendii [blades forming an angle 30-40° with respect to the culm] and more spreading in S. anglica [blades forming an angle of 30-60°with respect to the culm], and this character is noted in many of the recent field identification resources for the Pacific Northwest. Leaf angle is sometimes difficult to determine on herbarium specimens. Marchant (1968a) also noted swards of Spartina anglica in the field (in England) differed from swards of Spartina xtownsendii as being less dense in tillers (ca. 52/100 cm2 vs. ca. 96/100 cm2) and having more robust but fewer rhizomes.

Spartina anglica can be distinguished from Spartina alterniflora by its longer spikelets [(15-)16.5-25 mm long vs. 8-14(-16.5) mm long], moderately to densely pubescent glumes (vs. glabrous or weakly pubescent glumes) and its longer anthers (7-10 mm long vs. 3-6 mm long). Spartina anglica is readily distinguished from Spartina densiflora , Spartina gracilis , Spartina patens and Spartina pectinata by its glabrous leaf blade margins [vs. scabrous leaf blade margins].

Pollen fertility.

Determining pollen fertility by staining anthers with lactophenol cotton blue is a useful way to distinguish male sterile hybrid plants from those that are fertile, as the cytoplasm of fertile pollen grains readily takes up the stain whereas sterile (i.e., aborted) pollen grains do not. Pollen staining is thus an effective, though more technically involved method, to definitively distinguish the fertile Spartina anglica from the sterile F1 hybrid Spartina xtownsendii , as demonstrated by Marchant (1968a). To confirm identifications of these taxa here, and to demonstrate the utility of this technique, I determined pollen fertility for multiple herbarium specimens of Spartina anglica and Spartina xtownsendii using lactophenol cotton blue; collections examined in this manner are identified with the symbol † in the specimen list below and under Spartina xtownsendii . One to three anthers were sampled from a spikelet on each specimen, and these were macerated with forceps in a drop of water on a glass slide to release the pollen. One or a few drops of lactophenol cotton blue were added to the slide and after sitting for a minimum of ten minutes, the slides were examined at 20 × to 60 × magnification with a compound microscope. In general, the number of pollen grains recovered per specimen varied with the stage of pollen development. For example, in specimens of Spartina anglica that had been collected during or after dehiscence, fewer pollen grains were available for study, whereas in Spartina xtownsendii dehiscence does not occur and abundant pollen grains were recovered from the anthers. In fertile pollen grains the cytoplasm was evidently visible and stained, whereas in sterile pollen there was no or little evidence of cytoplasmic staining ( Fig. 5 ). All plants that were determined morphologically to be Spartina anglica had fertile pollen, and all plants determined as Spartina xtownsendii had sterile pollen.

Specimens examined.

Canada. British Columbia: Greater Vancouver Regional District: Lower Fraser Valley, Boundary Bay, foot of 104th Street, 49°02'00"N, 122°56'00"W, 26 May 2004, P.Lim s.n. (V [V191319]); Lower Fraser Valley, Boundary Bay, foot of 112th Street, 49°02'00"N, 122°56'00"W, 16 Jun 2004, P.Lim s.n. (V [V191320]]); Delta, Boundary Bay Regional Park, off 12th Avenue, 49°00'N, 123°02'W, 30 Jul 2004, G. Williams 2004 -3 (UBC [UBCV220132†, Suppl. Fig. 4], V [V191495]); Delta, 50 m E of Beach Grove dike, Boundary Bay, 49°02'N, 123°03'W, 30 July 2004, G. Williams 2004 -2 (CAN [CAN592131†, Suppl. Fig. 5], UBC [UBCV220131†, Fig. 3 ], V [V191494]); Robert Banks Causeway, S shore, 49°05'N, 123°11'W, 30 Jul 2004, G. Williams 2004 -1 (UBC [UBCV220130†, Suppl. Fig. 6], V [V191493]). United States of America. Washington: Island Co.: W side of Cornet Bay mudflat N of group camp in Deception Pass State Park, NE ¼ of NE ¼ of Sec. 35, T.34N, R.1 E., 7 Aug 2008, J.Walker 382 (WTU [WTU373426†, Suppl. Fig. 7], Suppl. Fig. 7); Puget Sound, Whidbey Island, N shore of Kennedy’s Lagoon, E side of Route 525, SW of S end of Zylstra Road, 48°14'N, 122°43.9'W, 22 Aug 2002, P.F.Zika 17595 (WTU [WTU365225†, Suppl. Fig. 8); Livingston Bay, Iverson Spit, 48°13'26"N, 122°26'19"W, 20 July 1983, R.E.Frenkel 3045 (UBC [UBCV196071†, Suppl. Fig. 9], WTU [WTU305390†, Suppl. Fig. 10]). Jefferson Co.: intertidal zone on the N side of the mouth of Chimacum Creek on the Quimper Peninsula, T29N R1W S35, 2 Aug 2004, F.Weinmann & A.Weinmann 233 (WTU [WTU370619†, Suppl. Fig. 11]). Snohomish Co.: island at W end/mouth of Ebey’s Slough, 48°02.555'N, 122°12.535'W, 15 Sep 2005, D.Giblin & B.Legler 244 (WTU [WTU364297†], Suppl. Fig. 12); mouth of Hat Slough, S side, 48°11.782'N, 122°22.463'W, 23 Sep 2005, D.Giblin & B.Legler 270 (WTU [WTU364317†], Suppl. Fig. 13); Puget Sound, Camano Island, E side of Davis Slough, N side of Route 532, 1.5 air km W of Stanwood, 48°14.4'N, 122°23.3'W, P.F.Zika 19170 (WTU [WTU355103†], Suppl. Fig. 14). Denmark. Jutland,NE coast of Rømø, 55°08'N, 08°31'E, 25 Aug 1970, I.B. Jørgensen & J.Svendsen 368 (CAN [CAN358861†, Suppl. Fig. 15]). England. England, 1879, H.Groves & J.Groves s.n. (US [US747577]); Poole Harbour, Fitzworth Point, R.O.Sherring s.n. (US [US1271872]). Devon Co.: South Devon, Combeinteignhead, between Newton Abbot and Teignmouth, ca. 50°32'N, 03°32'W, 24 Aug 1979, G.A.Matthews s.n. (CAN [CAN448159†, Suppl. Fig. 16]). Dorset Co.: Poole, 50°43'N, 01°59'W, Oct 1905, W.H.J.Riddelsdell 1734 (CAN [CAN467908†, Suppl. Fig. 17]); Dorset, E of Poole Harbour, 50.6863°N, 2.0181°W uncertainty 2195 m, Sep 1910, H.S.Thompson s.n. (UBC [UBCV1679, Suppl. Fig. 18]). Hampshire Co.: Hayling Island, Hants, 50.7999°N, 0.9667°W uncertainty 7194 m, 20 July 1938, T.M.C.Taylor 5378 (UBC [UBCV69243, Suppl. Fig. 19, UBCV20934, Suppl. Fig. 20]); between the “Sturt” Pond, [illegible], and Hurst Castle, South Hants, Sep 1910, J.C.Melvill 1841 (UBC [UBCV1678, Suppl. Fig. 21]); Lymington, towards Lymington Spit almost one mile from land, G.Stapf s.n. (US [US1271838]); Hythe, S of town and near road and Admiraly buildings, 28 Jun 1961, C.E.Hubbard 286961 (US [US3055889]). Isle of Wight, near Quarr Abbey, Oct 1907, O.Stapf (US [US1271833]). FRANCE. Baie de Mont Saint Michel, Sep 1933, P.de la Varde s.n. (US [US1611439]); mouth of river at Saranelle, near Cannes, 43°33'05"N; 07°00'45"W, Oliver s.n. (CAN [CAN421006†, Suppl. Fig. 22]).

Figures

Figure 3. Photograph of a specimen of Spartina anglica collected in Boundary Bay, south of Vancouver, British Columbia (Williams 2004 - 2, UBC). Image published with the permission of the University of British Columbia Herbarium, Beaty Biodiversity Museum.

Figure 4. Anthers of a Spartina anglica [U. S. A., Washington, Pacific Co., Zika 17595, WTU], bar = 3 mm. b Spartina xtownsendii [England, Hythe, Southampton, Marchant s. n., UBCV 221074], bar = 3 mm. Anthers of Spartina anglica are fully exserted at anthesis, dehiscent, and the pollen is fertile. The longitudinal splitting of the anthers is a good indicator of dehiscence. Anthers in Spartina xtownsendii are not or incompletely exserted at anthesis, indehiscent, and the pollen is sterile. Photos: J. M. Saarela.

Figure 5. Pollen stained with lactophenol cotton blue. a, b Spartina anglica, fertile pollen [Canada, British Columbia, Williams 2004 - 3 (CAN)] c Spartina xtownsendii, sterile pollen [England, Hampshire, 1877, Groves s. n. (CAN)] d Spartina xtownsendii, sterile pollen [Canada, British Columbia, Saarela & Percy 791 (CAN)]