Festuca longifolia Thuill. ( F. glauca auct. non Vill., F. glauca var. caesia (Sm.) Howarth, F. caesia Sm.)
2005; Wiley; Volume: 93; Issue: 1 Linguagem: Inglês
10.1111/j.0022-0477.2004.00963.x
ISSN1365-2745
Autores Tópico(s)Botany and Plant Ecology Studies
ResumoPoaceae, Subfamily Pooideae (Festucoideae), Tribe Poeae. Perennial grass producing dense tussocks, usually glabrous, without rhizomes. Culms smooth (or rough with prickles near the panicle), grooved in distal half; with 2(−3) nodes near the base, the uppermost usually hidden beneath subtending sheath, erect or slightly bent near the base, 7–45 cm tall; sheaths (0.9–4.2(−5.1) cm) fused for 10–33% of their length, smooth and glabrous; with short, glabrous to occasionally minutely ciliate auricle; ligule < 0.5 mm, glabrous or ciliate. Tillers all intravaginal; leaves usually strongly glaucous, pruinose, rigid to fairly rigid, tightly infolded, 2–12(−45.5) cm long, 0.55–0.9 mm from midrib to edge, mostly 7–(−9) nerved, distinctly ribbed above (4–6 adaxial grooves), rough to almost smooth, bluntly keeled and tapering to a fine tip. Panicles 2.4–8.0(−12) cm long, erect, dense or very dense, with 11–27 spikelets, branches pruinose, narrowing or not below the spikelets, usually smooth, but occasionally scabridulous, sparsely covered in hairs or prickles; 1st or 2nd panicle nodes 0.6–1.5 cm apart on flowering stem. Pedicels 0.5–1.8 mm. Spikelets pruinose; 5.4–7.5 mm long, with (2–)3–6(−8) florets, plus one sterile floret. Glumes unequal; lower narrowly triangular, 1.7–2.5 mm long, 1-nerved; upper narrowly lanceolate to oblong-lanceolate (2.6–)2.8–3.5(−3.8) mm long, 1–1.1 mm wide, 3-nerved. Lemmas lanceolate (3.5–)3.6–4.4(−4.8) mm long, 1.4–1.5(−2) mm wide, 5-nerved, mucronate or with fine awn (0.5–)0.9–1.5 mm long. Paleas linear-lanceolate (3.5–)−3.7–4.5 (−4.8) mm long. Anthers yellow or purple, 1.8–2.6 mm long. Caryopses (grains) c. 3 mm, tightly enclosed by the hardened lemma and palea (Fl. Eur. 5; Kerguélen & Plonka 1989; Wilkinson & Stace 1991; Sell & Murrell 1996; Stace 1997). Mean caryopsis oven-dry weight 0.37 mg. Native. This is a complex species that has been confused with other members of the Festuca ovina aggregate until clarification by Auquier & Kerguélen (1977) and Wilkinson & Stace (1991). The name Festuca glauca Vill. has often been wrongly applied to this species (Stace et al. 1992). The name Festuca glauca is correctly applied to the garden ‘Blue Fescue’. Treatments of F. longifolia by Tutin (1952, 1962) and Hubbard (1954, 1968, 1984) relate to F. lemanii Bastard and F. brevipila Tracey rather than F. longifolia sensu Thuill. Extensive reports of F. longifolia in the agricultural literature probably refer to the > 20 cultivars of ‘hard fescue’ (F. brevipila) (syn. F. trachyphylla (Hack.) Krajina) (Alderson & Sharp 1993; Huff & Palazzo 1998) that are widely planted for erosion control and soil improvement (see, e.g. Richardson & Evans 1986). The literature reporting on F. longifolia non Thuill. is not considered here. Festuca longifolia Thuill. was typified by Auquier & Kerguélen (1977) who selected a lectotype in Herb. Delessert (G). Subspecies F. longifolia ssp. longifolia Thuill. and ssp. pseudocostei Auquier & Kerguélen are recognized, with the latter limited to north-east France and Luxembourg (Auquier & Kerguélen 1977; Kerguélen & Plonka 1989). Trist (1973) considered that two putative varieties (of F. caesia), var. glauca and var. caesia, originally described in 1808 by Sir J.E. Smith from the English Breckland, were most likely caused by response to local soil conditions (see also Trist 1976). The salient features of F. longifolia that allow it to be differentiated from close relatives, especially F. brevipila and F. glauca, are its dense habit, strongly pruinose, glaucous and smooth leaf-blades, moderately dense to fairly lax panicles, pedicel length (longer than F. glauca, shorter than F. brevipila), glabrous sheaths, diploid chromosome number and discontinuous, broken ring of sclerenchyma (= 5 main islets) (Stace 1991; Wilkinson & Stace 1991). Festuca longifolia also has a glabrous ligule, open sheaths, ovate-lanceolate upper glume, and an awn allowing it to be distinguished from F. inops De Not. in the European flora (Fl. Eur. 5). The disjunct distribution of Festuca longifolia in the British Isles is shown in Fig. 1. It occurs on sandy heaths and acid grasslands in sixteen 10-km squares in Great Britain and six in the Channel Isles (Hill et al. 2004). Festuca longifolia is highly restricted to a few sites in the Breckland of W. Suffolk in East Anglia, a few sites in north and coastal Lincolnshire, one site in Nottinghamshire, several sites in S. Devon, a site in Cornwall, and Jersey, Guernsey, Alderney, Sark, and Herm in the Channel Islands. In continental Europe, it occurs on the maritime cliffs of Normandy in north-western France (Provost 1998). Records from the 1930s also report F. longifolia from acid heathlands in that area. Additional records of F. longifolia from France include the River Seine valley near Paris, river valleys of the Loire and Cher, and parts of the Pyrénées (Kerguélen & Plonka 1989). Festuca longifolia has been reported from Belorussia (Kruganova et al. 1970), and the description of this record appears to match that described for the species by Wilkinson & Stace (1991); however, such a substantial range extension must be viewed with caution, especially since the authors synonymize their plant with F. trachyphylla Krajina (= F. brevipila Tracey of Wilkinson & Stace 1988). The distribution of Festuca longifolia in the British Isles. Each dot represents at least one record in a 10-km square of the National Grid. Native: (•) 1950 onwards; introduced (+) 1950 onwards. Mapped by H.R. Arnold, using A. Morton's DMAP program, Biological Records Centre, Centre for Ecology & Hydrology, Monks Wood, mainly from data collected by members of the Botanical Society of the British Isles. Preston & Hill (1997) classify F. longifolia as one of 48 species in the Oceanic Temperate floristic element of Britain and Ireland. In Britain, native stands of F. longifolia occur at 5–10 m altitude at Spalford Warren, Nottinghamshire and 15–30 m in the Brecklands, whereas in Devon it occurs on clifftops at 160–200 m. The population at Fishcombe Point, Devon, however, extends from the top of the headland (20 m) down to the high-tide level on the south-facing cove wall. Cliff-top populations of F. longifolia in the Channel Islands are all 75–90 m above sea level. In continental Europe, F. longifolia is reported from 15 m above sea level on the cliffs in Normandy (Provost 1977) to an altitude of 1800 m in the Pyrénées (Kerguélen & Plonka 1989). Festuca longifolia grows under a range of climatic conditions from the frost-free habitats of south Devon and the Channel Islands to the low rainfall, droughty conditions of the Brecklands. Long hours of sunshine characterize all habitats. Mean January temperature in the 10-km squares in which F. longifolia is found (excluding Cornwall) is 4.8 °C, mean July temperature is 16.2 °C, and annual precipitation is 751 mm (Hill et al. 2004). In the Brecklands, Festuca longifolia occurs on flat to gently sloping ground, generally road verges, although some populations occur on more extensive areas such as Foxhole Heath. On the Normandy cliffs, F. longifolia is recorded from 0° to 30° S, SW and NW-facing slopes (Provost 1977), whereas in Devon, Cornwall and in the Channel Islands its distribution is limited to flat parts of southerly facing rocky, cliff tops and headlands. The Devon cliffs are of the ‘whaleback’ type with F. longifolia occurring on the flat rock exposed on the cliff tops. Festuca longifolia is confined in Britain to loose, sandy soils inland and thin, immature cliff-top soils on the coast. The soil of the Breckland sites was recorded by Trist (1973) with a pH of 4.5 and low in P and K. The Nottinghamshire population is on soil derived from post-glacial blown sand. The sea cliff populations in south Devon occur on thin, dry soils over both micaschist (pH 4.7–5.3) and hornblende-chlorite schist (pH 5.3–6.1) rocks (Smith & Margetts 2001). Average soil nutrient levels for the MC5c subcommunity (see Section III) in which F. longifolia occurs in Devon are reported as: Na 48 ± 10, K 12 ± 1.0, Mg 36 ± 5, Ca 32 ± 8 and P 4.3 ± 1.3, all µmole g−1 (Rodwell 2000). Two Devon sites near Brixham are on Torbay limestone (pH 7.3–8.5) (Smith & Margetts 2001). In Guernsey, the thin, organic, cliff-top soils underlain by granite where F. longifolia occurs are acidic (Jee 1982). On the Devon schists and Channel Island granites, F. longifolia occurs in thin soils on rock debris, at the foot of sloping rock slabs, in rock crevices of a line fracture, or in a fissure of a flat ledge (Trist, in litt.). In Cornwall, F. longifolia occurs on Devonian and Lower Carboniferous dolerite or basalt greenstone. In France and Luxembourg, F. longifolia ssp. pseudocostei is reported from soils with pH 6.0–6.4, and a base-rich soil with pH 8.0 (Auquier & Kerguélen 1977). On the rocky headlands of Normandy, France, F. longifolia (reported as F. caesia) occurs on eroded Cambrian and Ordovician Period schists and is considered one of the species best adapted for latter stages in the succession from loose rock to a consolidated substrate (Provost 1977). In Normandy, F. longifolia was also reported as a dominant grass with Sesleria caerulea in turf on the exposed crests of chalk cliffs (Proctor 1958). However, F. longifolia in this account was synonymized with F. duriuscula auct. non L. which is now recognized as F. lemanii Bastard or F. brevipila Tracey (Wilkinson & Stace 1988, 1991). Nevertheless, the wide pH range occupied by F. longifolia suggests that it is not an obligate calcifuge, but likely restricted to xeric habitats which are environmentally stressful for other species (Smith & Margetts 2001). Festuca longifolia is a species of acid heaths and maritime cliffs. In Britain, F. longifolia is not listed as a component of plant communities as originally defined by the National Vegetation Classification (Rodwell 1991, 2000; although see Rodwell et al. 2000). In Britain, F. longifolia communities can be assigned to U1 Festuca ovina–Agrostis capillaris–Rumex acetosella grassland, particularly the U1b Typical subcommunity in the Breckland (Table 1). The open, tussocky U1 grassland occurs as a mosaic of subcommunities distinguished by grazing intensity and underlying soil. Festuca longifolia populations are frequent in the grazed subcommunities of U1 such as the U1d Anthoxanthum odoratum–Lotus corniculatus subcommunity at Foxhole Heath (Pakeman & Marshall 1997). The occurrence of Teesdalia nudicaulis, Erodium cicutarium, Ornithopus perpusillus and other ephemeral plants at some sites may reflect a transition to the species-rich U1c Erodium cicutarium–Teesdalia nudicaulis subcommunity. The U1 vegetation type is maintained through regular grazing and the changes to ranker, less species-rich vegetation following the cessation of grazing were described by Watt in a series of studies (e.g. Watt 1971a). The two extant F. longifolia sites in Lincolnshire are also most closely assigned to U1 grassland because of the presence of two of the three constant species typical of this vegetation type, i.e. F. ovina and Rumex acetosella (although the third, Agrostis capillaris, is absent), and several characteristic associates of the U1c and U1d subcommunities including Arenaria serpyllifolia, Carex arenaria and Cerastium arvense (Table 1). Similarly, the Nottinghamshire site is a mesic U1 grassland heath dominated by Deschampsia flexuosa and Carex arenaria that shares floristic affinities with the Breckland grass heaths. The cliff-top populations of F. longifolia in south Devon and Cornwall occur as open patches of U1 grassland in close association with dense H8 Calluna vulgaris–Ulex gallii heath. In the most exposed areas where salt-spray influence is the greatest, the U1 grassland patches are replaced by the MC5 Armeria maritima–Cerastium diffusum ssp. diffusum maritime therophyte community, particularly the MC5c Aira praecox subcommunity. In patches where Festuca rubra is common these may have the composition of MC8 Festuca rubra–Armeria maritima maritime grassland. Festuca longifolia replaces the more typical F. ovina in these maritime communities. These cliff-top communities occur as mosaics over excessively drained shallow soils (1–15 cm, Rodwell 2000) around rock outcrops and in rock crevices. Even though these areas may be open to grazing, the cliff-top habitat is typically out of reach of the stock, and in most cases rarely visited by the public as the coastal pathway is 50 m or more lower down the cliff. Vascular species associated with F. longifolia are recorded in Table 1. Achillea millefolium, Carex arenaria, Festuca ovina, Galium verum and Plantago lanceolata were present in more than 60% of site lists from the Breckland. Rare species associated with F. longifolia include Phleum phleoides and Veronica verna recorded from Breckland sites (Trist 1979). Dactylis glomerata was the most frequent of 85 associates in Devon populations of F. longifolia, with Hypochaeris radicata, Plantago coronopus and Sedum anglicum constant on all three rock types, and Armeria maritima restricted to the schists (Table 1). Bryophytes associated with F. longifolia in Devon populations include Pseudocrossidium revolutum and Hypnum lacunosum on limestone, and Campylopus introflexus, Polytrichum juniperinum and Hypnum cupressiforme over schist bedrock. Twenty-eight associates were noted around plants of F. longifolia on the exposed, rocky cliff at Nare Head, Cornwall, including many of the same associates noted in Devon populations (Table 1). In the Channel Islands, F. longifolia occurs in wind-swept cliff-top grassland sward including Cytisus scoparius ssp. maritimus, Dactylis glomerata, Trifolium campestre and Vulpia bromoides, and cushions of Armeria maritima, Silene uniflora and Sedum anglicum (Jee 1982; Trist 1996 in Smith & Margetts 2001). The nationally scarce Lotus subbiflorus has been observed in the same location as Festuca longifolia on Sark (C. Stace, pers. comm.). In north-west France, F. longifolia is reported as a companion species in the Tuberario maritimae-Romuleetum columnae association of the European Atlantic coastal cliff domain (Provost 1977). Trist (1973, 1979) notes that F. longifolia is palatable to rabbits but that it can ‘survive grazing’. Festuca longifolia is sensitive to competition from larger plants. Declines in abundance and, in some cases, extirpation at several sites in the Breckland have been linked to shading, crowding, and competition for soil moisture, often due to a decline in rabbit grazing (Trist, in litt.). Festuca longifolia grows in dense clumps, although in dry grassland the clumps appear to degenerate in the centre and are difficult to distinguish one from another. Within populations, F. longifolia tends to occur as individuals scattered among the sward. Festuca longifolia is a S/CSR plant according to Grime's scheme (Hodgson et al. 1999). Ellenberg values for F. longifolia in Britain are light 8, water 3, reaction 5, nitrogen 2 and salt 0 (Hill et al. 2004). Trist (1979) noted that plants growing in open places, in patches of Cladonia, and on the sides of rabbit runs, were depauperate with only 1–3 culms and short blue-green (compared with the usual greyish-green) leaves (5–7 cm). Plants showing these characteristics were at one time described as Festuca glauca var. caesia (Sm.) K. Richt. until Trist (1973) showed them to be edaphic variants of F. glauca var. glauca Lam. (= F. longifolia Thuill.). In fertile garden soils the leaves of glaucous-leaved transplants became longer, less strongly curved, and a greyish-green compared with plants in native sandy, Breckland soils (Trist 1973). Panicle length is also short (1.3–2.8 cm) in var. caesia plants in the wild compared with those in cultivated conditions (4.5–5.0 cm). Spikelet length was invariant (5.0–7.0 mm). A comparison of Festuca longifolia plants from among populations in Devon (Table 2) indicated that plants growing in the shade of other plants were larger with longer leaves, taller culms and with more spikelets per culm than plants growing in adjacent exposed areas. Open-grown plants over limestone had taller culms than open-grown plants over schist. Cliff-top F. longifolia plants from the Channel Islands were similar in size to open-grown cliff-top plants from Devon. Trist (in litt.) found Breckland F. longifolia plants to include specimens smaller than those from Devon (panicle length 1–7.5 cm and 4.5–6.5 cm, respectively), while French plants spanned the range of both (panicle length 1.5–10 cm). Population densities may be quite variable in the Breckland as, from 1991 to 1995, the number of plants observed in grassy verges varied from 25 to 40 plants at West Stow Cottages, and from 210 to 106 at West Stow, King's Forest (Y. & D. Leonard, unpublished data, 2001). Perhaps the largest Breckland population of F. longifolia is on Foxhole Heath, Eriswell, Breckland, where Trist (in litt.) observed 1390 plants in a 130 × 5 m section of a gulley in July 1995. Festuca longifolia populations declined in Breckland sites from which rabbit grazing was excluded following the smothering growth of tall grasses, including Anisantha sterilis and Arrhenatherum elatius. On the coastal cliffs of the Channel Islands, population sizes are small, reflecting the discontinuous nature of suitable habitat. Individual populations there average 5–10 plants (Trist, in litt.). In south Devon, the coastal cliff populations vary from 2 to 3 plants to > 100. Trist (1979) noted that F. longifolia is drought resistant and able to develop in dense competition from other plants. However, young seedlings are susceptible to drought. In Devon and Cornwall, F. longifolia occurs in the most xeric open areas of otherwise gorse-dominated cliff-top headland. Plants of F. longifolia are densely tufted and all vegetative shoots are intravaginal, retaining the old leaves (Wilkinson & Stace 1991). Stomata (29–31 µm, Kerguélen & Plonka 1989; Wilkinson & Stace 1991) and prickle-cells are present only on the adaxial leaf surface, silica-cells are present on both leaf surfaces, and cork-cells are restricted to the abaxial leaf epidermis (Wilkinson & Stace 1991). Stomatal density of the adaxial surface of leaves from glasshouse-grown plants raised from seed collected from Foxhole Heath was 240 ± SE 8 mm−2 (30 measurements). Most plants bear < 5 panicles; however, a single large tussock in Breckland was observed with 69 flowering stems 29–37 cm height with 4.5–7 cm length panicles (D.J. Gibson, unpublished data, 2001). Glasshouse-grown seedlings of F. longifolia from Foxhole Heath, Breckland, sown in February 2002, showed a rapid increase in size, developing 38–57 leaves and 10–12 vegetative tillers each by 77 days, and 87–120 tillers each by 108 days. Increase in leaf and tiller numbers of the most vigorous seedling through 77 days approximated a third degree cubic polynomial (leaf number =−0.1 + 0.08 (days since sowing) + 0.01 (days since sowing – 34.8)2 + 0.0004 (days since sowing – 34.8)3, r2 = 0.99, P = 0.001, n = (10). Roots fibrous, mostly < 10 cm in length, but can extend to > 20 cm. Fresh roots of plants growing over schist in south Devon were brown (7.5 YR hue with 5/6–6/4-value/chroma when dry becoming 5/4–5/6 when wet (Munsell Color Charts, Anonymous (undated)). Root samples collected from Festuca longifolia plants growing over mica-schist and hornblende-chlorite schist from Bolberry Down and Lannacombe Bay, south Devon, showed 10–50% AM fungal colonization of the fine roots including extensive production of vegetative fungal hyphae internally and externally, plus vesicles and a few arbuscules internally (D. J. Read, pers. comm.). Festuca longifolia is a hemicryptophyte. Vegetative growth of mature plants is slow. It reproduces exclusively by seed which is ready for dispersal in mid-summer. Individuals do not appear to flower annually (Trist 1973). Fragments of clumps can form new individuals, but whether this occurs or not in the field is unknown. Glasshouse-grown clumps when divided showed > 75% mortality with survivors initially growing very poorly. 2n = 2x = 14 (material from Guernsey and France, Wilkinson & Stace 1991, and from Cornwall, J. P. Bailey, unpubl. data). B-chromosomes absent (Wilkinson & Stace 1991). By comparison, the frequently confused ‘hard fescue’Festuca longifolia non Thuill. (= F. brevipila) and the much cultivated F. glauca have 2n = 42 chromosomes (Auquier & Rammeloo 1973; Auquier & Kerguélen 1977; Wilkinson & Stace 1991). A tetraploid individual (2n = 28) from the Le Mans (Sarthe) region of north-east France was reported with the characteristics of F. longifolia, but was considered to be probably an undescribed, related taxon (Auquier & Kerguélen 1977). Festuca longifolia is a cool-season grass possessing the C3 photosynthetic pathway. Mineral element concentration of dry leaves from 3-year-old glasshouse-grown plants (n = 3) from Foxhole Heath, Breckland, was recorded as 2.10–3.27% N, 0.35–0.48% P, 1.76–2.56% K, 0.16–0.29% S, 0.14–0.22% Mg, 0.27–0.31% Ca, 0.01–0.02% Na, and 27–30 µg/g B, 54–67 µg/g Zn, 66–159 µg/g Mn, 45–51 µg/g Fe, 7–14 µg/g Cu and 14–17 µg/g Al. These levels are low for some of the macronutrients (P and Mg) and for the micronutrients Fe and Na, but high for the micronutrient Mn, compared with the congeners Festuca arundinacea and F. pratensis, and some other pasture grasses (Whitehead 1966; Deakins 1979). The percentage N content indicates a crude protein content of 13.1–20.4%, comparable to other pasture grasses (Deakins 1979). No information available. Festuca longifolia flowers in June–July in Breckland sites, with seed-bearing panicles maturing in mid-July (D.J. Gibson & I. Taylor, personal observation). Earlier flowering has been observed in the more southerly populations. Cliff plants growing on a rocky surface were recorded flowering on 15 May from Pleinmont and Saint's Bay, Guernsey (P. Ryan 1986, herbarium specimen in La Société Guernesiaise). Trist (in litt.) collected plants on 24 April, 1994 with culms fully exserted and open panicles from Prawle Point and Gammon Head, Devon. One of these plants, after overwintering in a pot in Brabham, Cambridgeshire, exserted two culms also on 24 April, 1995, but following a cold spring did not open its panicles until 15 May with anthesis on 24 May. Naturally established plants at Caversham, in Breckland, had their inflorescences only half exserted on 2 June of that year. At the time of flowering, fresh basal leaves have taken the place of overwintering leaves which have died. Individuals do not flower every year, and flowering appears unrelated to total annual rainfall (Trist 1973). Plants grown from seed in the glasshouse lacking a winter freeze did not flower in the first four years. Plants grown in pots outdoors in Leicester flowered from late April to early May in 1985, and anthesis occurred between 8:00 and 8:30 h (Wilkinson 1986). Auquier (1977) showed this species (as F. caesia, from France and the Breckland) to be an outbreeder with self-fertility levels of less than 1%. Wilkinson (1986) found two plants to be completely self-sterile and a third (all from Foxhole) to be 5.2% self-fertile. Festuca longifolia ssp. pseudocostei is considered to have arisen through introgressive hybridization between F. longifolia ssp. longifolia and the calcicole F. hervieri (St-Yves) Parzke (Auquier & Kerguélen 1977). These authors also report that experimental crosses with other taxa in the F. ovina group support the recognition of F. longifolia as a species. Wilkinson (1986) was unable to raise hybrids of F. longifolia with F. hervieri, F. ovina, F. filiformis, F. heteropachys or F. armoricana. The unit of dispersal is a caryopsis 3 mm long and 1 mm wide. Average 1000 seed weight (air dry), 0.8 g (Tweddle et al. 2003). The principal dispersal agent is unassisted (barochory), although seeds may also be dispersed by birds and wind (Trist 1973). With either 3–6 or 2–8 (see first page) florets per spikelet and 11–27 spikelets per panicle (Wilkinson & Stace 1991), this suggests an output of between 22 and 216 grains per panicle. Propagules are spikelets disarticulating above the glumes at maturity as groups of one to several florets. Seeds collected from Devon and placed on filter paper moistened with distilled water in Petri dishes at 26/16 °C under a 12/12 photoperiod showed the first signs of germination after 48 h. Seed collected from Breckland sites (Foxhole Heath and West Stow) in July 2001 and stored at 4 °C for 6 months showed a 50% germination after 2 weeks when placed on moist paper towels at room temperature. After 34 months at 4 °C, the seed from Foxhole Heath showed 40% germination under 125 µmoles m−2 s−1, 22/15 °C, 14/10 photoperiod, humidity 95% whereas seed from nearby West Stow (< 10 km away) did not germinate at all. Seed collected from Devon populations and stored for 6 months in a laboratory refrigerator showed 30–50% germination after 6 weeks on filter paper moistened with distilled water in Petri dishes under conditions of 26/16 °C, 12/12 photoperiod. 100% germination of seed was obtained by Tweddle et al. (2003) with the germination medium 1% Agar with 101 mg L−1 potassium nitrate. Constant temperatures (21 °C) in the absence of potassium nitrate decreased germination to 80%. Only 50% germination was obtained following pre-sowing treatments including seed sterilization (immersion in 10% sodium hypochlorite for 5 min), and seed scarification (covering structure removed) in a germination medium of 1% Agar under germination conditions of 20 °C and a 12/12 photoperiod. At RBG Kew, Wakehurst Place, viable seed has been stored under IGPRI preferred conditions for 16 years (Tweddle et al. 2003). Seed storage of Festuca longifolia is described as ‘orthodox’, indicating that seed can be dried, without damage, to a low moisture content and remain viable. In germinating seed, the radicle appeared first, and the grain was pushed upright as the lower glume remained on the surface of the filter paper (Fig. 2). Germination of new seed continued through 38 days although 66% of eventual germination had occurred within 10 days. The second true leaf appeared after 17 days, with the third leaf not appearing in even the most advanced seedlings until 33 days (Fig. 2). By 43 days when the experiment was terminated, seedlings had branched primary roots. Dispersal units and seedlings of Festuca longifolia: (a) dry caryopsis, various views; (b) after germination for 3 days with primary leaf emerging from the coleoptile; (c) after 8 days; (d) after 23 days; and (e) after 48 days. Seed collected from Devon. All to the same scale with each illustration made from a representative seedling. Rabbits and sheep. Uredinales The rust Puccinia festucae Plowr. infects the leaves (Ellis & Ellis 1985). Hyphomycetes Hyphae of a species of Neotyphodium (Acremonium) Glenn, Bacon & Hanlin were detected at low frequency in a leaf sheath stained with aniline blue from F. longifolia specimens collected from Foxhole Heath, Breckland. This observation was confirmed following a positive result on seed from this population tested using an immunoblot assay specific for Neotyphodium cell wall proteins (Agrinostics, Inc., Watkinsville, GA). This test also detected the Neotyphodium endophyte epitopes in F. longifolia seed collected from Bolberry Down and Fishcombe Bay, Devon, but not in seed from a population above Lannacombe Bay, Devon (see Table 1 for locations). Variation in endophyte presence among populations located within 30 km is comparable to that observed in other fescues (e.g. Gibson & Newman 2001; Spyreas et al. 2001; Gibson & Taylor 2003). Neotyphodium (Epichloë) typhina (Morgan-Jones & W. Gams) Glenn, Bacon & Hanlin and Epichloë festucae Leuchtm., Schardl & M.R. Siegel are reported from several cultivars of ‘hard fescue’ (F. longifolia auct. non Thuill.) (Saha et al. 1987; Bacon & Siegel 1988; Christensen et al. 1997). The endophytes in the Festuca ovina complex are asymptomatic Type III mutualists (White 1988; White & Baldwin 1992). Festuca longifolia was first diagnosed by Thuillier (1799) (fide Auquier & Kerguélen 1977) as ‘F. tota albicanti-glauca; folis subsetaceo-longissimis; panicula subspicata: spiculis 4–6 floris, glabris, aristatis’. In Britain, F. longifolia was first recorded (as F. caesia) by Sir J.E. Smith from ‘heaths around Bury’ June 15, 1804 (Sowerby & Smith 1808; Trist 1973). Owing to its restricted distribution (Fig. 1), Festuca longifolia is a species of serious concern in Britain, classified as ‘rare’ with a conservation status of ‘vulnerable’ (Hill et al. 2004), and classified within the IUCN category ‘vulnerable’ (Wigginton 1999; JNCC 2004). Dolman & Sutherland (1992) listed it as a Breckland indicator species. They attributed a 39% decline in sites in which it occurred in the 20th century to habitat change, mainly succession to rank grassland following reductions in sheep or rabbit grazing. As with other Breckland rarities, e.g. Veronica spicata ssp. spicata (Wilson et al. 2000), the open sward obtained under high grazing pressure appears necessary to maintain populations of reproducing F. longifolia. Other sites have been lost owing to increased vehicular disturbance along roadside verges. Foxhole Heath (TL 735 774), 1.5 km south-east of Eriswell, West Suffolk, is designated a Site of Special Scientific Interest (SSSI) because of its unique Breckland flora (Watt 1971b), the presence of nesting stone curlews, and its possession of the largest population of F. longifolia in the British Isles. Similarly, the Nottinghamshire site at Spalford Warren (SK 831 678) is designated an SSSI because of the restricted inland occurrence of Deschampsia flexuosa grass heaths. The population of F. longifolia at Spalford Warren consisted of approximately 21 plants in August 2002 (I. Taylor, personal observation) limited to the roadside verge at the edge of the site. In south Devon, many of the F. longifolia populations occur in the Prawle Point and Start Point SSSI, part of the South Devon Area of Outstanding Natural Beauty, and Heritage Coast, a 12 km stretch of coastline of national importance for its geology, lichens and invertebrates. The Cornwall population at Nare Head is owned by the National Trust and is part of the Fal and Helford candidate Special Area of Conservation. The British Ecological Society provided funding to DJG for fieldwork. Yvonne and David Leonard kindly showed us the Breckland sites and shared with us their observations of this species. Simon Dunsford showed us populations in south Devon. Ian Bennallick provided information on the newly discovered population in Cornwall. We are grateful to the Estate of the late P.J.O. Trist for allowing us to see his unpublished papers on Festuca longifolia, referred to in this paper as Trist (in litt.) that are on deposit at SCRC, Morris Library, SIUC. Bridget Ozanne of La Société Guernesiaise kindly loaned herbarium specimens. Anne Bonis and Michel Provost provided information on French populations. Simon Stainer provided bryophyte identifications. David Read kindly screened root samples for AM colonization. Eric Lees measured the Devon specimens and provided the leaf stomata counts. Kathy Millar and Andrew Wood conducted the endophyte assay. Richard Cole and Karen Frailey maintained F. longifolia plants in the glasshouse. Illustrations for Fig. 2 were prepared from scanned photographs by the Southern Illinois University Carbondale IMAGE facility. Voucher specimens of Festuca longifolia from the Devon and Breckland populations are deposited in the herbarium of Southern Illinois University Carbondale. Tony Davy, Michael Proctor, Clive Stace and David Streeter commented on the manuscript. We thank Arthur Willis for his encouragement to undertake this review and critical comments on the manuscript.
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