Bothriochloa macra (Steud.) S.T.Blake
red-leg grass
Loosely or densely tufted, sometimes rather straggling, geniculate at base with erect culms; branching intravaginal. Leaf-sheath pale creamy green to light brownish, subcoriaceous, keeled, glabrous, rarely with one or two long, fine, tubercle-based hairs towards base near margin, or sparsely hairy throughout. Ligule 0.5-1 mm, finely ciliate. Leaf-blade 4.5-8 cm × 2-3 mm, lanceolate, scabrid-papillose and with long, fine, sparse, tubercle-based hairs, keel prominent; margins minutely scabrid, often with a few, long, fine, tubercle-based hairs near ligule; long-tapered to acuminate tip; culm-leaves subpseudopetiolate. Culm (15)-20-60-(80) cm, nodes usually pubescent, internodes occasionally with scattered hairs below inflorescence. Racemes (2)-3-(4), subdigitate, 2-6 cm, naked near base for c. 0.5 cm, erect or curving but not spreading, shortly pedunculate, peduncles 2-5.5 mm, occasionally sparsely hairy, usually with a few hairs in axils between racemes; spikelet pedicels 3-4 mm, margins densely ciliate. Pedicelled spikelet Ø: 2.5-4.5 mm, consisting of glumes only; lower glume 7-9-nerved, linear-lanceolate, subobtuse, margins and nerves near tip ciliate-scabrid, upper usually much shorter, hyaline; rarely lower pedicelled spikelets ♂ with small hyaline lemma and 3 stamens, anthers c. 2 mm. Sessile spikelet: 4.5-5.5 mm, greenish purple, surrounded at base by callus hairs to 1 mm, glumes thinly coriaceous, lower = spikelet, 5-7-nerved, linear-lanceolate, with scattered hairs especially in lower ½, tip obtuse with short stiff hairs, glume not pitted but sometimes with a depression at centre, upper slightly shorter, finely scabrid on keel near tip; lemma of lower floret c. ¾ length of glumes, ovate-lanceolate, tip erose; lemma of upper floret, narrow at base and topped by a stout, brown, geniculate 20-30 mm awn; palea 0; stamens 3, anthers 1.2-1.8 mm; gynoecium: ovary 1-1.2 mm, stigma-styles 3.5-4 mm; caryopsis c. 2.5 mm, purplish, embryo c. 1 mm, hilum basal c. 0.3 mm.
N.: North Auckland to Auckland City, Cuvier Id, Gisborne; S.: Nelson, Marlborough. Dry grassy hillsides near coast.
Naturalised from Australia.
Formerly known as Dichanthium annulatum.
Seeds of Australian B. decipiens (Hack.) C.E.Hubb., pitted bluegrass, were listed as impurities in imported commercial seed [Healy, A. J. Standard Common Names for Weeds in N.Z. ed. 2, 133 (1984)] but plants are not known to occur in the wild in N.Z. This 1-anthered sp. in which the lower glume of the sessile spikelet is usually pitted, is closely allied to B. macra and may be confused with it.
