Bromus sp. aff. diandrus
3-veined lower glume
Bromus sp. aff. diandrus
3-veined lower glume
Vegetative form. Annual. Leaves scattered along the culms. Culms 45-69 cm high, 2-3 noded or 5 noded. Mid-culm nodes glabrous. Mid-culm internodes hollow, glabrous, terete. Leaves non-auriculate. Basal leaf sheaths not keeled, terete, puberulous to pilose (often sparsely), with margins connate, in lower 2/3s, hyaline, ciliate. Ligule 2-3.5 mm long, hyaline, smooth, acute to obtuse, erose, abaxially glabrous. Collar glabrous, or puberulous to pilose. Leaf blades flat, linear, 70-220 mm long, 2-6 mm wide; sparsely adaxially puberulous to adaxially pilose; sparsely abaxially puberulous to abaxially pilose; with margins scabrous to with margins ciliate, apices acuminose, flat.
Reproductive organization. Plants bisexual. Incomplete spikelets absent. Inflorescence of cleistogamous spikelets.
Inflorescence. Inflorescence a raceme to a panicle (sometimes with a reduced spikelet between panicle arms), open. Main inflorescence axis 330-470 mm long. Peduncles 150-335 mm long, acropetally shortly puberulous (trichomes retrorse or antrorse). Rachides 70-160 mm long, subterete, puberulous to pilose. Rachis angles puberulous to pilose. Primary inflorescence branches slightly spreading to divaricate or reflexed (with age), verticillate, with spikelets inserted at the base. Spikelets 2 per node. Spikelets 1-2 on a typical ultimate inflorescence branch, on first order branches.
Hermaphrodite (`perfect') spikelets. Hermaphrodite spikelets pedicellate, 27-35 mm long, laterally compressed or not noticeably compressed, obovate, disarticulating as a separate unit, disarticulating above the glumes. Pedicels 5-60 mm long. Glumes two per spikelet, free, similar, subequal. Lower glume c. 3/4s the length of the upper glume, narrowly oblong, 16.5-21 mm long, 0.75-1.5 mm wide, membranous, acropetally keeled or dorsally rounded, long acuminate to acute, muticous, margin hyaline to margin membranous (broad), margin smooth; 2-3 veined (often appearing as 1 veined, the lateral vein(s) may be obscure), midvein scabrous; intercostal regions glabrous, or intercostal regions puberulous (sparsely). Upper glume narrowly oblong, 22-31 mm long, 1-2 mm wide, membranous to chartaceous, acropetally keeled, long acuminate to acute, muticous, margin hyaline to margin membranous (broad), margin smooth; 3 veined or 5 veined (3 0f which are prominent), veins obscure or veins prominent (slightly), acropetally midvein scabrous; intercostal regions glabrous. Incomplete florets present, distal to the hermaphrodite florets. Hermaphrodite florets 6 per spikelet. Rachilla disarticulating between the florets, disarticulating directly below the florets, straight, sparsely and minutely scabrous, elongated between all florets, apically prolonged. Callus present, pointed, 0.75-1.25 mm long, glabrous to scabrous (minutely). Lemma similar in firmness to the glumes, narrowly ovate to narrowly elliptic, 17-30 mm long, 1.5-3 mm wide, chartaceous, acropetally keeled, long acuminate to acute, bifid, 2 -lobed, awned. Lemma margins minutely scabrous. Lemma 7 veined. Lemma veins confluent towards the apex, obscure or prominent, connected by obscure transverse veins to not connected by transverse veins, scabrous, with the hairs on all the veins, with the hairs extending the length of the veins; intercostal regions scabrous, the hairs over the entire dorsal surface. Awns 1, median. Median awn much longer than the body of the lemmas, 40-60 mm long, 3 veined, apical, straight, scabrous. Palea fully developed, slightly shorter than the lemmas, similar in texture to the lemmas, tightly clasped by the lemmas, narrowly elliptic to narrowly obovate, 8-15.5 mm long, 1.5-2 mm wide, hyaline to membranous, 2-keeled, keels wingless, acuminate to acute, entire; 2 veined, veins scabrous; intercostal regions glabrous, or intercostal regions papillose (minutely), or intercostal regions puberulous. Lodicules 2, free, hyaline, acute to obtuse, with entire margins, glabrous. Stamens 2-3. Anthers 0.75-1 mm long or 3.5 mm long, basally 2-lobed. Ovary with a conspicuous apical appendage, pilose, with the hairs only at the apex. Styles 2, free to their bases. Distal incomplete florets 3 per spikelet, neuter, merely underdeveloped, awned, paleate or epaleate.
Fruit. Fruit adhering to lemma and adhering to palea (more so to the palea), elliptical, dorsiventrally compressed, 12-14 mm long, 1.5-2.5 mm wide, slightly ventrally longitudinally grooved or not grooved, pilose, with dense hairs, the hairs confined to a terminal tuft. Hilum 10.5-11.5 mm long, linear. Embryo 1.5-1.75 mm long.
Abaxial leaf blade epidermis. Leaf anatomical data recorded.
Costal/intercostal zonation conspicuous; the intercostal zones bordering the midrib 25-27 cells wide; epidermis differentiated into long- and short-cells; long-cells of similar wall thickness costally and intercostally.
Microhairs absent.
Crown cells absent. Prickles present; intercostal and marginal; antrorse and retrorse; fairly uniform in size and form. Prickle bases not paired with a short-cell. Intercostal prickles in the astomatal files. Bases of the intercostal prickles longer than the width of an intercostal long-cell; about as long as the stomata; barbs of the intercostal prickles more than twice as long as the bases. Macrohairs present; intercostal; intergraded with long prickles; unicellular; robust; with thickened walls; sparse but frequent; more than twice as long as an intercostal long-cell. Macrohair bases attached at cuticle only; uniform in mode of insertion.
Intercostal long-cells fairly constant in shape. Mid-intercostal long-cells markedly elongated; fusiform; inflated; long-cell walls straight; end walls vertical, or angled; the intercostal long-cell walls not conspicuously pitted. Papillae absent.
The costal zones all histologically similar; costal short-cells conspicuously in long rows, or solitary. Costal silica bodies present and perfectly developed; cuboid silica bodies confined to the outer edges of costal zones, or confined to the central files of the costal zones (the horizontally elongated silica-bodies); horizontal-crenate, horizontal-smooth, and cuboid.
Intercostal short-cells rare or infrequent, or absent; when present, confined to the outer regions of the intercostal zones; solitary. Unsilicified intercostal short-cells square; walls straight. Intercostal silica bodies absent, or imperfectly developed; when present, cuboid.
Stomata common; present in all the intercostal zones; distributed throughout the intercostal zones; arranged in definite rows. Stomatal rows in the widest intercostal zones 4; evenly dispersed. Stomata 57-62-69 m long; with guard-cells overlapped by the interstomatals. Subsidiaries dome-shaped to parallel-sided. The domes low.
Photosynthetic pathway and related features. C3. XyMS+. The PBS sheaths of the primary lateral vascular bundles interrupted. Mestome sheath single; complete.
Transverse section of the leaf blade. Lamina mid-zone in transverse section open; more or less flat, or more or less flat to V-shaped. Width of lamina across a primary vascular bundle 138-179.4-234 m. Lamina mid-zone in transverse section exhibiting adaxial ribs only. Adaxial furrows slight; wide. Adaxial furrows between all the vascular bundles. Adaxial ribs more or less constant in size, or irregular in size; round topped; opposite all vascular bundles. Vascular bundles in the mid-lamina 22-30; 1 per rib. Abaxial furrows absent.
Midrib pronounced in outline; adaxially raised and rounded; prominent abaxially. Vascular bundles in the mid-lamina region of the midrib 1. The median vascular bundle with a protoxylem cavity; with an enlarged protoxylem vessel; with sclerosed phloem. Midrib without colourless tissue adaxially (but the adaxial linking sclerenchyma always contains large, relatively thin-walled cells); 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, or absent as discrete groups but the epidermis extensively bulliform. The bulliform groups situated when present, between vascular bundles. The bulliform groups without contiguous colourless mesophyll cells; small; simple, fan-shaped (of irregulary-shaped cells). Abaxial epidermis of bulliform-like epidermal cells.
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, or without adaxial sclerenchyma; without abaxial sclerenchyma, or with abaxial sclerenchyma (rarely, as girders or strands); the adaxial sclerenchyma when present, forming girders, or forming strands; the smallest vascular bundles lacking sclerenchyma. The adaxial sclerenchyma of the mid-lamina all associated with vascular bundles.
Vouchers. Specimens examined morphologically: M.Carter 429: 0.1km S. from intersection of Yerramullah and Cantabilling Rd. (W.A.); 9.x.1985; Fl.; CANB, PERTH - R.Pullen 4185: C.S.I.R.O. grounds, Black Mtn, Canberra (A.C.T.); 15.xi.1966; Fr.; CANB - D.E.Symon 6573: Mortlock experimental stn. (S.A.); 8.xi.1968; Fr.; ADW, CANB - D.E.Symon 3534: Jettner property "Markaranka", Morgan (S.A.); 7.x.1965; Fr.; ADW, CANB - D.E.Symon 13289: c. 2 km NW. of Milang (S.A.); 13.x.1983; Fr.; ADW, CANB, DAV - D.E.Symon 9595: Innes National Park, Yorke Peninsula (S.A.); 7.x.1974; Fl.; ADW, CANB - K.J.Knight 260: Corner of Greystone St. & Leach highway, Wilson (W.A.); 17.x.1984; Fr.; CANB, PERTH - R.J.Cranfield 13: S. end of Garden Is (W.A.); 20.x.1978; Fr.; CANB, PERTH.
Material examined anatomically: D.E.Symon 6573 SA CANB; M.Carter 429 WA CANB; R.Pullen 4309 Blk Mtn ACT CANB (listed as diandrus by Murray).
Classification. Triticodae; Bromeae.
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.