Briza subaristata Lam., Encycl. 1: 187 (1791).

T: e Monte-Video, Commers. Spicul. virid.

Vegetative form. Perennial (?), caespitose. Leaves scattered along the culms. Culms 28-50 cm high, unbranched above, 2-3 noded. Mid-culm nodes glabrous. Mid-culm internodes hollow, glabrous, terete. Leaves non-auriculate. Basal leaf sheaths not keeled, terete, glabrous, commonly the same colour as the lamina or purple (sometimes), with margins free, hyaline, smooth. Ligule 1.5 mm long, hyaline, smooth, acuminate to acute, entire to erose. Collar glabrous. Leaf blades involute (at least when dry), linear, 120-200 mm long, 1-2.5 mm wide; minutely adaxially scabrous; abaxially glabrous; with margins scabrous, apices acute.

Reproductive organization. Plants bisexual. Incomplete spikelets absent. Inflorescence of apparently cleistogamous spikelets.

Inflorescence. Inflorescence a panicle, contracted (but not strongly so), oblong. Main inflorescence axis 215-345 mm long. Peduncles 140-315 mm long, minutely scabrous. Rachides 70-100 mm long, strap-like to subterete, glabrous to scabrous. Rachis angles scabrous. Primary inflorescence branches spreading, spiral (but several branches arising from the one node). Spikelets 2 on a typical ultimate inflorescence branch, on third order branches.

Hermaphrodite (`perfect') spikelets. Hermaphrodite spikelets subsessile, 1.75-4 mm long, laterally compressed or not noticeably compressed (especially after anthesis), ovate, disarticulating as a separate unit, disarticulating above the glumes. Pedicels 2-8.5 mm long. Glumes two per spikelet, free, similar, equal in length. Lower glume narrowly obovate, 2 mm long, 0.75-1.25 mm wide, chartaceous, dorsally rounded, shortly acute, muticous, base cordate, margin hyaline, margin smooth; 3 veined, veins obscure, minutely midvein scabrous; intercostal regions glabrous to intercostal regions papillose. Upper glume elliptic, 2.5 mm long, 1-2 mm wide, chartaceous, dorsally rounded, shortly acuminate to acute, muticous, base cordate, margin hyaline, margin smooth; 5 veined, acropetally midvein scabrous; acropetally intercostal regions glabrous to intercostal regions scabrous. Incomplete florets present, distal to the hermaphrodite florets. Hermaphrodite florets 6-8 per spikelet. Rachilla disarticulating between the florets, disarticulating directly below the florets, flexuous, glabrous, elongated between all florets, apically prolonged. Callus present, blunt, 0.1 mm long, glabrous. Lemma similar in firmness to the glumes, broadly obovate to broadly elliptic, 2.5-2.75 mm long, 2-3.5 mm wide, chartaceous, acuminate, emarginate, 2 -lobed, muticous to mucronate or awned (shortly). Lemma margins smooth. Lemma 7 veined. Lemma veins not confluent apically, obscure, minutely papillose, with the hairs on the midvein, with the hairs only at the vein apex; intercostal regions minutely papillose, the hairs only at the apex. Awns 1, median. Median awn shorter than the body of the lemmas, 0-0.5 mm long, curved (usually recurved), glabrous. Palea fully developed, 1/2 the length of the lemmas, similar in texture to the lemmas, tightly clasped by the lemmas, broadly elliptic, 1.25 mm long, 1 mm wide, membranous to chartaceous, 2-keeled, shortly keels winged or keels wingless, acute to obtuse, entire; 2 veined, minutely veins scabrous; intercostal regions glabrous. Lodicules 2, free, hyaline, acuminate to acute, toothed, with margin divisions terminal, glabrous. Stamens 3. Anthers 0.25-1.75 mm long, basally 2-lobed. Ovary without a conspicuous apical appendage, glabrous. Styles 2, free to their bases. Distal incomplete florets 4 per spikelet, neuter, merely underdeveloped, awnless, epaleate.

Fruit. Fruit broadly obovoid, ventrally compressed (i.e. on the palea side), 0.75 mm long, 0.5 mm wide, glabrous. Hilum 0.1 mm long, punctiform (to elliptic).

Abaxial leaf blade epidermis. Leaf anatomical data recorded.

Costal/intercostal zonation conspicuous; the intercostal zones bordering the midrib 10-12 cells wide; epidermis differentiated into long- and short-cells; long-cells similar in shape costally and intercostally; long-cells of similar wall thickness costally and intercostally (fairly thick-walled).

Microhairs absent.

Crown cells absent. Prickles present; intercostal, costal, and marginal, or costal and marginal (only); antrorse; fairly uniform in size and form. Prickle bases paired with a short-cell (costally), or not paired with a short-cell (intercostally). Costal prickles along all zones; frequent in their files. Costal prickles not over-arching the intercostal zones; bases of the costal prickles about as long as the width of an intercostal long-cell; barbs of the costal prickles shorter than the bases. Intercostal prickles when present, in the astomatal files; infrequent. Bases of the intercostal prickles about as long as the width of an intercostal long-cell; barbs of the intercostal prickles well formed, but shorter than the bases. Macrohairs absent.

Intercostal long-cells fairly constant in shape. Mid-intercostal long-cells markedly elongated; rectangular to fusiform; hexagonal; long-cell walls tessellate; the undulations regular; end walls vertical; the intercostal long-cell walls associated with conspicuous pitting; outer surfaces of intercostal long-cells not pitted. Papillae absent.

The costal zones all histologically similar; costal short-cells predominantly as cork/silica cell pairs. Costal cork-cells similar in shape to the silica cells; square, or tall-and-narrow; longitudinal width of costal cork-cell/silica-cell pairs 15-19.5-27 m. Costal silica bodies present and perfectly developed; throughout the costal zones; more or less round, cuboid, and crescentic (rarely).

Intercostal short-cells common; throughout the intercostal zones; paired; longitudinal width of intercostal cork-cell/silica-cell pairs 10.5-13-15 m. Intercostal cork-cells tall-and-narrow to square, or crescentic. Intercostal silica bodies present and conspicuous; more or less round, tall and narrow-smooth, and crescentic.

Stomata absent, or infrequent (only one seen); if present, about 30 m long. Subsidiaries dome-shaped to parallel-sided. The domes low.

Photosynthetic pathway and related features. C3. XyMS+.

Transverse section of the leaf blade. Lamina mid-zone in transverse section open; more or less flat. Width of lamina across a primary vascular bundle 183-222 m. Lamina mid-zone in transverse section exhibiting adaxial ribs only. Adaxial furrows deep; wide. Adaxial furrows between all the vascular bundles. Adaxial ribs more or less constant in size; flat-topped; opposite all vascular bundles. Vascular bundles in the mid-lamina about 15; 1 per rib. Abaxial furrows absent.

Midrib pronounced in outline; adaxially raised and rounded; prominent abaxially; 1 keeled abaxially; tissue layout similar to that of other primary vascular bundles. The median vascular bundle with a protoxylem cavity; with an enlarged protoxylem vessel; with sclerosed phloem. Midrib without colourless tissue adaxially; without thin-walled sclerenchymatous cells adaxially; without lacunae. The lamina symmetrical on either side of the midrib.

Mesophyll chlorenchyma non-radiate; tightly packed. Mesophyll without lacunae; without any obvious adaxial palisade; without `circular cells'; not traversed by columns of colourless cells; without arm cells; without fusoids. Bulliforms present in discrete groups. The bulliform groups situated between vascular bundles. The bulliform groups without contiguous colourless mesophyll cells; small; simple, fan-shaped. Abaxial epidermis without bulliform-like epidermal cells or groups. Abaxial epidermal cell walls thickened. The cells regular in shape, rounded, or regular in shape, ovoid.

The major vascular bundles interspersed with minor bundles; outlines of primary vascular bundles more or less circular; primary vascular bundles centrally situated. Primary lateral vascular bundles with adaxial sclerenchyma; with abaxial sclerenchyma; the adaxial sclerenchyma forming girders; the abaxial sclerenchyma forming girders; the combined girders forming I's. Outlines of lower order vascular bundles more or less circular. Lower order vascular bundles centrally situated; with adaxial sclerenchyma; with abaxial sclerenchyma; the adaxial sclerenchyma forming girders; the abaxial sclerenchyma forming girders; the combined girders of the lower order vascular bundles forming I's; the smallest vascular bundles with sclerenchyma. The adaxial sclerenchyma of the mid-lamina all associated with vascular bundles.

Vouchers. Specimens examined morphologically: R.Pullen 1933: Turner, Canberra (A.C.T.); 3.xi.1959; Fl.; CANB, MEL, NSW - R.Pullen 9557: Australian National University, Acton, Canberra (A.C.T.); 7.xi.1974; Fl, Fr.; CANB.

Material examined anatomically: A.C.T.: Turner, Canberra, 3.xi.1959 R.Pullen 1933 (CANB) (MEL) (NSW); Australian National University, Acton, Canberra, 7.xi.1974 R.Pullen 9557 (CANB).

Classification. Poodae; Poeae.

Cite this publication as:
C.M. Weiller, M.J. Henwood, J. Lenz and L. Watson (1995 onwards). `Pooideae (Poaceae) in Australia - Descriptions and Illustrations'. URL http://muse.bio.cornell.edu/delta/
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993) should also be cited.

References and Acknowledgements