Spartina xtownsendii H. Groves & J. Groves, Bot. Exch. Club Rep. 1880. 37. 1881.

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 : 48-51

Spartina xtownsendii H. Groves & J. Groves, Bot. Exch. Club Rep. 1880. 37. 1881.

Spartina xtownsendii H. Groves & J. Groves, Bot. Exch. Club Rep. 1880. 37. 1881. Type. England. Mud flats, near Hythe, South Hants, 1 Sep 1879, H.Groves s.n. (holotype: BM [BM001003965!]; isotypes: C, K [K000710272!], W [W19160030795!, W19160030798!] (ex hb. Groves), US [US1127161!] (fragm. ex W ex hb. Groves), US [US878793!]). Note: The location of the holotype has not been reported previously in the literature.

Spartina xneyrautii Fouc., Ann. Soc. Sci. Nat. Charente-Maritime 31: 8. 1894. Type. France. près de Hendaye ( Basses-Pyrénnées), E-J.Neyraut s.n., 24 Jul 1892 (isotypes: P [P00753804!, P03457326!, P03457334!, P03457416!], US! (fragm. ex P)]).

Description.

Culms 46-100 cm tall, thick, fleshy, rhizomatous. Sheaths glabrous; ligules 1-1.5 mm long; blades 6.5-37 cm long × 4-10 mm wide, flat proximally, often involute distally, divergent 30-40° from culms, adaxial surfaces glabrous, occasionally with very sparse hairs proximally, when present hairs to 0.2 mm long, abaxial surfaces glabrous, occasionally with sparse hairs proximally, when present hairs to 0.5 mm long, margins smooth. Inflorescences 10.5-24(-36) cm long × 7-25 mm wide at midpoint, erect, with (2)3-6(-10) branches; branches (6-)7.5-15(-18) cm long × (2.5-)3-4 mm wide, appressed or ascending, rachises 1-1.9 mm wide between spikelets, extending 2-10(-18) mm beyond the terminal spikelet, extension occasionally absent, glabrous, margins glabrous, occasionally with a few marginal hairs, when present hairs to 0.2 mm long. Spikelets 14-17.5 mm long × 1.5-2.5 mm wide, weakly appressed, weakly overlapping, calluses 0.6-1.5(-2) mm long. Glumes weakly to moderately pubescent, hairs 0.1-0.2 mm long, proximal hairs occasionally to 0.6 mm long, keels glabrous, ciliate or scabrous, when present hairs and teeth 0.2-0.5 mm long, usually longest proximally; lower glumes 7-13 mm long × 0.5-0.7 mm wide, 1-veined, tips acuminate or obtuse; upper glumes 12.5-16.5 mm long × 1-1.5 mm wide, 3-veined, tips acuminate or obtuse. Lemmas 9.5-13.5 mm long, 1-3-veined, pubescent distally, glabrous proximally, margins membranous, keels ciliate distally, hairs to 0.2 mm long, glabrous proximally. Paleas exceeding lemmas by ca. 1 mm, glabrous. Anthers 5-7(-8.5) mm long, not or incompletely exserted at maturity, indehiscent, medium to dark brown, pollen sterile; caryopses absent. 2 n = 62 ( Marchant 1963, 1968b).

Common name.

Townsend’s cordgrass.

Etymology.

The epithet townsendii was given in honour of the English botanist Frederick Townsend (1822-1905).

Illustration.

Cope and Gray 2009:547.

Distribution.

This species is found in England, Wales, Scotland, Ireland ( Cope and Gray 2009), Italy ( Scarton et al. 2003), United States (Washington), New Zealand ( Partridge 1987), and Canada (British Columbia).

Comments.

In the mid to late 1800s an unknown cordgrass of restricted distribution appeared and spread rapidly along the shores of Southampton Water, England ( Stapf 1914), which differed morphologically (particularly by its sterile pollen) from Spartina maritima , the single cordgrass species native to the Atlantic coast of Europe and north Africa ( Marchant and Goodman 1969c), and the introduced Spartina alterniflora , which had been present in the region since the early part of the 19th century. The brothers Henry and James Grove (1881) described this taxon as Spartina townsendii from plants collected near Hythe. In the 1890s a second form of Spartina townsendii , which was recognized and considered distinct by having fertile stamens, was collected at multiple localities in the region, and by the mid twentieth century it had expanded substantially on tidal flats across the British Isles (see Goodman et al. 1959, Hubbard 1957, 1965). For decades these two forms (one sterile, the other fertile) of Spartina townsendii were referred to collectively as the Spartina townsendii aggregate or Spartina townsendii sensu lato. Because of its vigorous growth and ability to rapidly colonize and stabilize mud flats, Spartina townsendii s.l. was considered to be a “useful” species and was distributed and planted widely for land reclamation, coastal protection, and animal feed across the British Isles, Europe, and in New Zealand (e.g., Oliver 1925, Harboard 1949, Goodman et al. 1959, Ranwell 1967).

Soon after its formal description Spartina townsendii was considered to be a species of hybrid origin. Foucaud (1894) suggested that Spartina townsendii was probably a hybrid of the native Spartina maritima and the introduced Spartina alterniflora , a hypothesis later supported by Stapf (1914) and Huskins (1930), who examined cytological evidence and hypothesized that fertile plants of Spartina townsendii s.l. originated from chromosome doubling following hybridization between its parent species. Marchant (1963) confirmed this work, and reported chromosome numbers as 2 n = 62 for Spartina alterniflora , 2 n = 60 for Spartina maritima , 2 n = 62 for sterile plants of Spartina townsendii , and 2 n = 120, 122, 124 for fertile plants of Spartina townsendii . The hybrid and chromosome doubling origins of the forms of Spartina townsendii have been confirmed by multiple lines of molecular evidence ( Guénégou et al. 1988, Raybould et al. 1991, Ferris et al. 1997, Ayres and Strong 2001, Baumel et al. 2003). Hubbard (1957) observed the type specimen of Spartina townsendii to be the sterile F1 hybrid, and the taxon was subsequently referred to as Spartina xtownsendii . The fertile plants remained without a name until Hubbard (1978) later described them as Spartina anglica , and the two forms have since been recognized as distinct taxa. Molecular data have identified Spartina alterniflora as the female parent and Spartina maritima as the male parent in the origin of Spartina xtownsendii (e.g., Ferris et al. 1997).

An independent origin of Spartina xtownsendii is documented in France. In 1894 Jules Foucaud described Spartina neyrautii Fouc. from southwestern France and northern Spain. Spartina neyrautii was initially considered to be a variant of Spartina maritima (e.g., Chevalier 1923, Saint-Yves 1932), but was later recognized as a morphologically and cytologically distinct hybrid, Spartina xneyrautii ,with the same parentage as Spartina xtownsendii (e.g., Jovet 1941, Chevalier 1933, Marchant 1977). Baumel et al. (2003) confirmed this with molecular data, demonstrating that Spartina xneyrautii and Spartina xtownsendii originated independently by hybridization between the same maternal ( Spartina alterniflora ) and paternal ( Spartina maritima ) taxa. Because both taxa apply to the hybrid Spartina alterniflora x S. maritima , the later name Spartina xneyrautii is a synonym of Spartina xtownsendii , in accordance with article H.2 of the Vienna Code ( McNeill et al. 2006), and as noted earlier by Raybould et al. (1990). In recent decades it has been documented that these hybrid plants are highly restricted in distribution in France ( Marchant 1977, Hubbard et al. 1978, Raybould et al. 1990, Baumel et al. 2003). Minor morphological differences between Spartina xneyrautii and Spartina xtownsendii were noted by Marchant (1977). Measurements of spikelet characters in Spartina xneyrautii type material examined at US fall within the range of variation reported here for Spartina xtownsendii .

Spartina xtownsendii has been introduced into North America, where apparently only a single occurrence has been reported in the literature. Hitchcock et al. (1969) noted a single known population of Spartina xtownsendii in Washington at Stanwood, Snohomish Co. At the time of that publication, the fertile (= Spartina anglica ) and non-fertile forms of Spartina xtownsendii were not distinguished taxonomically, and it is not explicitly clear from the flora which form of the taxon was known from the site. A specimen collected in 1965 from this population [Austenson s.n. (WTU, Suppl. Fig. 35)] is here confirmed to be the F1 sterile hybrid Spartina xtownsendii . The determination of a more recent collection from the Stanwood area identified as Spartina xtownsendii requires confirmation (Snohomish Co., Davis Slough west of Stanwood, 25 Aug 1990, M.Arnot 254, WTU-317391, not seen). A 2005 collection from Washington originally identified as Spartina xtownsendii (Giblin & Legler 270 WTU) is here re-determined to be Spartina anglica . Barkworth (2003) included Spartina xtownsendii in her treatment of Spartina for North America, but did not include a distribution map or otherwise indicate a range for the species, suggesting some confusion in the literature on its status in North America. Kozloff (2005) also included Spartina xtownsendii (as well as Spartina anglica ) in his Pacific Northwest flora, indicating only 'coastal salt marshes’ for its distribution. There apparently are no published data on the current status of the Stanwood population. If the population at Stanwood persists, new collections should be made to document its continued existence at the site, and if other populations are known or discovered, herbarium collections should be made to document their existences.

Spartina xtownsendii has not previously been reported from British Columbia. It is here reported as new for the province on the basis of two collections made in 2006 in in Boundary Bay at sites separated by some 4.4 kilometers (by air)[Taylor 80 (UBC, Fig. 11 ) and Saarela & Percy 791 (CAN, Fig. 12 , UBC, Suppl. Fig. 34)]. These appear to be the most recent confirmed reports of the taxon in North America since it was collected at Stanwood, Washington. Herbarium specimens of these collections were initially determined (incorrectly) as Spartina anglica and Spartina alterniflora , since Spartina xtownsendii was not expected in British Columbia. Subsequent study of this material, in combination with the Spartina taxonomic literature and comparisons with specimens of Spartina anglica and Old World specimens of Spartina xtownsendii at CAN and UBC, confirmed the specimens to be Spartina xtownsendii , prompting the current taxonomic study. Pollen in these specimens is sterile, as determined by pollen staining (see discussion under Spartina anglica , Fig. 5 ), further confirming their identities as Spartina xtownsendii . Specimens from which pollen was extracted and stained with lactophenol cotton blue to assess fertility are identified with the symbol † in the Specimens Examined below.

The origin of Spartina xtownsendii in British Columbia is not known, and there are no data on the extent of the Boundary Bay sub-populations in 2006 aside from notes on the Saarela and Percy collection label indicating a single clump of the grass approximately one meter in diameter. It is not known if Spartina xtownsendii has persisted in British Columbia since collected some five years ago. Since major efforts are ongoing to remove Spartina plants from Boundary Bay where Spartina xtownsendii was found, it is possible the original stands from which the specimens were collected have been removed. The region should be studied to determine if the taxon is present. Since the taxon is sterile and does not set seed, it must have been introduced into Boundary Bay by vegetative reproduction, probably from rhizome fragments transported in tidal currents. It is possible that the British Columbia plants originated from the stand at Stanwood, Washington, if it persists, or there may be other extant occurrences of Spartina xtownsendii somewhereto the south of Boundary Bay. Workers searching Puget Sound for invasive Spartina (e.g., Benbrook 2011) should be aware that Spartina xtownsendii may also be present.

Morphology.

The description here is based on the first known collection from Washington, the two collections from British Columbia, and Old World material housed at CAN and UBC (see Specimens Examined), including collections made by H. & J. Groves who first described the taxon over a century ago. The North American specimens of Spartina xtownsendii are morphologically similar to the Old World specimens examined. Spartina xtownsendii is distinguished from Spartina anglica by its shorter spikelets [(14-17.5 mm long vs. (15-)16.5-25 mm long]; shorter anthers [5-7(-8.5) mm long vs. 7-10 mm long]; indehiscent anthers that are not or incompletely exserted with sterile pollen [vs. dehiscent anthers that are usually fully exserted with fertile pollen; see Figs 4 , 5 ]; shorter ligules [1-1.5 mm long vs. 1-3 mm long]; upper glumes 3-veined [vs. upper glumes 3-6-veined]; and shorter upper glumes [12.5-16.5 mm long vs. 13-22 mm long]. The angle of the leaf blade with the stem is 30-40° in Spartina xtownsendii , compared to 30-60° in Spartina anglica ( Marchant 1968a). This character can be difficult to evaluate on herbarium specimens depending on how they were pressed, but should be more reliable in the field for distinguishing the taxa, particularly if they occur together. If stands of Spartina xtownsendii are relocated in British Columbia or elsewhere in the region, the taxonomic utility of this character should be carefully evaluated. Marchant (1968a) noted swards of Spartina xtownsendii to be distinct in appearance from swards of Spartina anglica in England, having high culm density and high tiller density (ca. 96/100 cm2 vs. ca. 52/100 cm2). It is not clear how Spartina xtownsendii differs morphologically from Spartina alterniflora x S. foliosa hybrids that have been documented in California ( Daehler and Strong 1997, Ayres et al. 1999, 2003, 2004, Anttila et al. 2000).

Specimens examined.

Canada. British Columbia: Greater Vancouver Regional District: Boundary Bay Regional Park, Boundary Bay, S of Richmond along trail off 12 Avenue in Tsawwassen, near 1st viewing platform, 49°01'28"N, 123°03'14"W, ca. 0 m, 28 Nov 2006, J.M.Saarela & D.M.Percy 791 (CAN [CAN590439†, Fig. 12 , UBC [UBCV228476†, Suppl. Fig. 34]); Greater Vancouver in marsh close to Undersea marshes and Pacific Flyway displays, Boundary Bay, 49°03'34"N, 123°01'27"W [secondary], 8 Nov 2006, T.Taylor 80 (UBC [UBCV222939†, Fig. 11 ). United States of America. Washington: Snohomish Co.:near Stanwood, ca. 48°14'N, 122°21'W, 26 Aug 1965, H.M.Austenson s.n. (WTU [WTU229915†, Suppl. Fig. 35]). England. Hampshire Co.: Hythe, South Hants, 9 Oct 1883, H.Groves s.n. (US [US555778]); Hayling Island, 13 Sep 1900, E.S.Marshall s.n. (CAN [CAN585633, Suppl. Fig. 36]); Southampton, 50°53'49"N, 01°24'15"W, Sep 1904, H.Groves & J.Groves 4596 (CAN [CAN251679†, Suppl. Fig. 37], US [US1535531]); Lymington, Keyhaven, 50°47'N, 00°58'W, 28 Aug 1977, G.Halliday 457/77 (CAN [CAN522593†, Suppl. Fig. 38]); Keyhaven, 50°43'22"N, 01°34'10"W, 30 Jul 1966, G.Halliday 100/66 (CAN [CAN301583, Suppl. Fig. 39]); Hants, Aug 1877, J.Groves s.n. (CAN [CAN421009†, Suppl. Fig. 40]); Hythe, Southampton, central marshes, male sterile, 50.8667°N, 01.3999°W uncertainty 7193 m, 10 Sep 1959, C.Marchant s.n. (UBC [UBCV221074, Suppl. Fig. 41]); N Hayling Island, Duckard Point, male sterile, 50.8051°N, 0.9778°W uncertainty 7194 m, 4 Aug 1960, C.Marchant s.n. (UBC [UBCV221101, Suppl. Fig. 42]); N Hayling Island, male sterile, 50.8051°N, 0.9778°W uncertainty 7194 m, 17 Aug 1961, C.Marchant s.n. (UBC [UBCV221098, Suppl. Fig. 43]); Eling, male sterile, 50.8999°N, 1.4833°W uncertainty 7193 m, 29 Aug 1961, C.Marchant s.n. (UBC [UBCV221100, Suppl. Fig. 44, UBC221095, Suppl. Fig. 45]); Hythe, south marshes, male sterile, 50.8666°N, 1.3999°W uncertainty 7193 m, 28 Oct 1959, C.Marchant s.n. (UBC [UBCV221093, Suppl. Fig. 46, UBCV221099, Suppl. Fig. 47]); Hythe, central marsh, near Sylvan Villa, giant male sterile, 50.8666°N, 1.3999°W uncertainty 7193 m, 16 Aug 1961, C.Marchant s.n. (UBC [UBCV221097, Suppl. Fig. 48, UBCV221096, Suppl. Fig. 49]); Hythe, Hants, male sterile, 50.8666°N, 01.3999°W uncertainty 7193 m, 10 Sep 1959, C.Marchant s.n. (UBC [UBCV221094, Suppl. Fig. 50]).

Figures

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)]

Figure 11. Photograph of a specimen of Spartina xtownsendii collected in Boundary Bay, British Columbia (Taylor 80, UBC). This is the first record of the taxon for British Columbia. Image published with the permission of the University of British Columbia Herbarium, Beaty Biodiversity Museum.

Figure 12. Photograph of a specimen of Spartina xtownsendii collected in Boundary Bay, British Columbia (Saarela and Percy 791, CAN). This is the second record of the taxon for British Columbia.