Elymus tenuis (Buchanan) Á.Löve & Connor
≡Agropyron scabrum var. tenue Buchanan Indig. Grasses N.Z. t. 57b et Add. & Corrig. 11 (1880)
≡A. tenue (Buchanan) Connor, N.Z. J. Sci. Tech. B35: 318 (1954);
Holotype: WELT 59620 (Buchanan's folio)!, no locality and no date.
Prostrate flat, bronze-leaved stoloniferous open grass, rooting and shooting from nodes on stolons; branching extravaginal; upper culm internode greatly elongating after anthesis and the long weak culm trails along the ground. Leaf-sheath 5-7 cm, glabrous or sometimes retrorsely pilose. Ligule 0.25-0.3 mm, very finely ciliate. Collar glabrous, curved and thickened. Auricles ± 1 mm or smaller, clasping, with 1-2 long hairs. Leaf-blade 10-15 cm × 2 mm, bronzed, flat sometimes ± involute, abaxially glabrous, smooth, ribs evident, adaxially with short antrorse prickle-teeth; margins prickle-toothed. Culm to 2 m, slender, trailing along ground, upper internode elongating after flowering sometimes reaching 1.5 m. Inflorescence 10-15 cm, of up to 15 spikelets. Spikelets 25-40 mm, of 6-8 florets. Glumes 9-15 mm, produced into barbed awn up to 3 mm, 3-nerved, keeled; margins shortly toothed. Lemma 6-10 mm, smooth except for prickles on central nerve, near bifid apex and on margins below; awn 15-35 mm. Palea 7-10 mm, apex pointed and bifid. Rachilla 1.5-2.5 mm, short hairy. Callus 0.5 mm, surrounded by short hairs. Lodicules 1.5-1.7 mm, linear, irregularly hair tipped. Anthers 2-3 mm, yellow. Gynoecium: ovary 1.25-1.5 mm; stigma-styles 2-2.5 mm. Caryopsis 4.5-5 mm; embryo 1 mm. 2 n = 56.
N.: Volcanic Plateau and Ruahine Range; S.: north-west Nelson, Marlborough and east of Main Divide to Southland. Open fescue-tussock grassland; sea level to 900 m.
Endemic.
HYBRIDISM
Natural Hybrids: The frequency of natural hybrids is not high and does not reflect the ease with which experimental hybrids can be made, or the frequency with which spontaneous hybrids can occur in experimental plots with close planting [Connor, H. E. Evolution 10: 415-420 (1956)].
E. solandri (n = 21) × S. gracilis (n = 14), × S. laevis (n = 14), and × S. deceptorix. All are vegetatively similar, and are alike in culm, inflorescence and spikelet morphology.
Slender, soft, stoloniferous grass with extravaginal branching. Leaf-sheath hairy. Auricles 0.75 mm, clasping, usually with a few long hairs. Ligule 0.3 mm. Leaf-blade thin, abaxially and adaxially with long hairs on ribs. Culm to c. 50 cm, smooth. Inflorescence to 10 cm, of 8-10 spikelets broadside to rachis. Spikelets to 20 mm, of 2-4 florets. Glumes ± equal 4-8 mm, narrow. Lemma 8-10 mm; awn 10-20 mm. Palea 8 mm. Rachilla 1.5-2.5 mm, hairy; rachilla prolongation to 3 mm. Anthers 2-2.5 mm; pollen sterile. Gynoecium: ovary to 1 mm; stigma-styles to 2.25 mm.
E. solandri × S. deceptorix CHR 358145 A. P. Druce Ada Valley, Spencer Mts, 3000 ft., Jan. 1979. E. solandri × S. gracilis CHR 323564 A. P. Druce Nina V(alley), S. of Lewis Pass, 2000 ft., Jan. 1978. E. solandri × S. laevis CANU 10831 C. J. Burrows Head of the Grebe, Jan. 1967, comprised E. solandri, S. laevis, and two inflorescences the spikelets and florets of which are longer than those in the combinations above. All are mounted separately in CANU.
E. ×wallii (Connor) Á.Löve et Connor, N.Z. J. Bot. 20: 183 (1982) ≡Agropyron ×wallii Connor, T.R.S.N.Z. 84: 757 (1957); Holotype: CHR 91921! H. E. Connor Porters Pass, Canterbury, 3000 ft, 5/1/56.
Perennial, stoloniferous. Branching intra- and extravaginal. Leaves up to 2 mm wide, blue-green, glaucous, villous; sheaths of basal leaves villous. Ligule short, truncate. Auricles clasping, villous. Culm 1 m, lax, ascending to drooping. Inflorescence to 12 cm, of 3-7 spikelets. Spikelets 25-40 mm, of 2-7 florets, > internodes. Glumes subequal, awn-tipped, 3-5-nerved. Lemma rounded on back, sharply indented at base, keeled and prickle-toothed at apex, 7.5-11.5 mm; awn 12-20 mm; apex of lemma and the awn frequently purple. Palea ≈ lemma, apex pointed, bifid. Callus bearded, obtuse, 0.5 mm. Rachilla 1.5-2.5 mm, finely setulose. Anthers 1.5-3 mm, yellow to purple. Pollen sterile. 2 n = 35.
S.: Canterbury, Porters Pass.
E. multiflorus × E. solandri Leaves are as in E. multiflorus. The spikelets are long with several florets. Lemmas bear scattered prickle-teeth, and awns are straight, 15-26 mm, and usually 1.5-2.5 × lemma length, except on the lowest floret in a spikelet. Palea apices are truncate to retuse. Mostly North Id.
Experimental Hybrids: Intergeneric hybrids are reported in Löve and Connor (1982 op. cit.). Interspecific hybrids: see Connor, H. E. 1956 op. cit., N.Z. J. Sci. 5: 116-119 (1962); Löve and Connor (1982 op. cit.); Lu, B.-R. and Bothmer, R. von Pl. Syst. Evol. 185: 33-53 (1993); Lu, B.-R. Pl. Syst. Evol. 186: 193-212 (1993). A list of intraspecific hybrids is given in Connor, H. E. N.Z. J. Sci. 5: 95-115 (1962) and Löve and Connor (1982 op. cit.).
This species is characterised by awned glumes and greatly elongating flowering culms.
GENOME ANALYSIS
The interpretation of the genome constitution of Australasian taxa by Torabinejad, J., Carman, J. G. and C. F. Crane Genome 29: 150-155 (1987), Agron. Abstr. 1989: 102 (1989); Torabinejad, J. and Mueller, R. J. Genome 36: 147-151 (1993), Theor. Appl. Gen. 86: 288-294 (1993); Lu and Bothmer (1993 op. cit.) all supersede that in Löve and Connor (1982 op. cit.). They show that the hexaploids contain the StY Elymus genome, even though the homology is often low, and the W genome of Australopyrum as the third component, and that the unique genomic formula is StYW where Y is of unknown diploid origin. For tetraploid E. enysii the H genome is proposed as one component but the second is unknown; it is not S [Svitashev, S. et al. Genome 39: 1093-1101 (1996)]. The octoploid E. tenuis has not been included in modern studies.
INCERTAE SEDIS
CHR 1613, no collector [possibly B. C. Aston], Omaka River [Marlborough], December 1915. "Has a blue tint when fresh, alsoplentiful on Waihopai where however Danthonia pilosa is the chief native grass". CHR 514886 G. Jane Flaxmere River, 4 Dec 1997.
Plants are short and tufted. Leaf-sheath softly hairy or glabrous. Leaf-blade flat or involute, adaxially shortly prickle-toothed; auricles long, clasping. Culm to 20 cm; glabrous, decumbent to erect. Inflorescence to 8 cm, of 5 overlapping spikelets 25 mm long with up to 6 florets. Glumes adaxially fine hairy. Lemma 9 mm, keeled almost to base, keel and nerves with small prickle-teeth above, apex toothed, awn 10 mm, straight. Palea < lemma, keels conspicuously toothed, apex truncate or retuse. Lodicules 1-1.3 mm, ciliate. Anthers 3 mm, purple. Gynoecium: ovary 1 mm; stigma-styles 2-2.5 mm.
These are unlike any other specimens of Elymus gathered in New Zealand, but the impression from Aston's label is of abundance; G. Jane's collection does not indicate frequency. They are certainly Australian in origin, and may be veritable E. scaber (R.Br.) Á.Löve.
CHR 214647 R. Mason & A. E. Esler 11643 Kerikeri Inlet Road [Northland], roadside, 29 Nov. 1970.
Stout, hairy 1.25 m. Leaf-sheath antrorsely long coarse hairy; auricles long, clasping. Leaf-blade green, with long coarse hairs or prickle-toothed on both surfaces. Culm 1 m, internodes slightly rough. Inflorescence 25 cm, of up to 20 overlapping spikelets; rachis margins and both surfaces prickle-toothed. Spikelets to 25 mm, of 6-7 florets. Glumes 6-7 mm, 5-nerved, prickle-toothed above. Lemma 7-9 mm, prickle-toothed throughout, apex toothed, awn straight, 15-25 mm. Palea 8-9 mm, apex ± cleft. Callus bearded only on upper margins. Anthers 2.7 mm; pollen fertile. Seed is set.
The habit is of E. rectisetus, but does not conform in palea apex, awn length and bearding of callus. It is probably introduced here.
CHR 327990 B. Matthews 33/78 Te Paki Trig, North Auckland, grassland 1000 ft, 29 Dec. 1978.
Leafy shoots from many-noded stems. Leaf-sheath glabrous; auricles 1.5 mm, clasping. Leaf-blade long-hairy or prickle-toothed. Culm to 50 cm, internodes becoming smooth. Inflorescence 11 cm, of 6-8 spikelets, rachis margin very strongly prickle-toothed and upper (convex) surface equally so. Spikelets to 35 mm, up to 5 florets. Glumes 4-6 mm, broad, sometimes emarginate, 3-5 evident prickle-toothed nerves, prickle-teeth above. Lemma 9.5 mm, abundantly prickle-toothed, awn to 22 mm. Palea 9.5 mm, apex truncate. Lowest floret in spikelet awnless, often < palea. Seeds setting.
This specimen possesses many E. multiflorus characters but the awn is very long and awn:lemma = 2.32. It may possibly be a segregate from a hybrid E. multiflorus × E. solandri or a backcross generation.
