Bromus inermis Leyss., Fl. Halens. 16 (1761).

T: in pratis succulentis fertilissimis im Fürstengarten in den Pulverweiden frequens: fl Iunio, Iulio. 19.

Vegetative form. Perennial, rhizomatous. Leaves scattered along the culms. Culms 123 cm high, unbranched above, 4 noded. Mid-culm nodes hairy (indumentum extends 2-3 mm either side of the node). Mid-culm internodes hollow, glabrous (except either side of the node), terete. Leaves non-auriculate. Basal leaf sheaths not keeled, terete, glabrous, strongly with margins connate, at least in lower 2/3s (splitting c. 10 mm below the ligule), membranous to chartaceous (of the free portions only), smooth. Collar glabrous. Leaf blades flat, linear, 375-400 mm long, 9-11 mm wide; adaxially glabrous; abaxially glabrous; with margins scabrous, apices acuminose.

Reproductive organization. Plants bisexual. Incomplete spikelets absent.

Inflorescence. Inflorescence a panicle, contracted. Main inflorescence axis 600 mm long. Peduncles 350 mm long, glabrous. Rachides 280 mm long, terete, glabrous. Primary inflorescence branches spreading, verticillate, with spikelets inserted at the base or without spikelets inserted at the base. Spikelets 1-4 on a typical ultimate inflorescence branch, spiral (?), on first order branches or on second order branches, spreading.

Hermaphrodite (`perfect') spikelets. Hermaphrodite spikelets pedicellate, 25-30 mm long, not noticeably compressed, oblong, disarticulating as a separate unit, disarticulating above the glumes. Pedicels 6-20 mm long. Glumes two per spikelet, free, similar, equal in length. Lower glume narrowly ovate, 8.5 mm long, 1 mm wide, membranous to chartaceous, keeled, acuminate to acute, muticous, margin hyaline, margin smooth; 1 veined, midvein scabrous; intercostal regions glabrous. Upper glume narrowly ovate, 11 mm long, 1.25 mm wide, membranous to chartaceous, keeled, acuminate to acute, muticous, margin hyaline, margin smooth; 3 veined, veins obscure, midvein scabrous; intercostal regions glabrous. Incomplete florets present, distal to the hermaphrodite florets. Hermaphrodite florets 5-7 per spikelet. Rachilla disarticulating between the florets, disarticulating directly below the florets, straight (internodes not acropetally expanded), minutely scabrous to puberulous, elongated between the glumes to elongated between all florets, apically prolonged. Callus present, blunt, 0.5 mm long, glabrous. Lemma similar in firmness to the glumes, narrowly elliptic to narrowly obovate, 13-13.5 mm long, 1.5-2 mm wide, chartaceous, keeled, acute, emarginate, 2 -lobed, awned. Lemma margins smooth. Lemma 7 veined (only 3 of which are prominent). Lemma veins confluent towards the apex, prominent, connected by obscure transverse veins, scabrous, with the hairs on all the veins, with the hairs extending the length of the veins; intercostal regions papillose, the hairs over the entire dorsal surface. Awns 1, median. Median awn shorter than the body of the lemmas, 2.5 mm long, 1 veined, arising from the sinus, straight, scabrous. Palea fully developed, about slightly shorter than the lemmas, thinner than the lemmas, tightly clasped by the lemmas, narrowly elliptic, 10 mm long, 1.25 mm wide, membranous, 2-keeled, acute to obtuse, entire; 2 veined, veins scabrous; intercostal regions glabrous. Lodicules 2, free, hyaline, obtuse, toothed or with entire margins, with margin divisions lateral, glabrous. Stamens 3. Anthers 4.25-4.75 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 1 per spikelet or 2 per spikelet, neuter, shortly awned, paleate.

Fruit. Fruit pilose, with dense hairs, the hairs confined to a terminal tuft.

Abaxial leaf blade epidermis. Leaf anatomical data recorded.

Costal/intercostal zonation conspicuous; the intercostal zones bordering the midrib 12-25 cells wide; epidermis differentiated into long- and short-cells; long-cells similar in shape costally and intercostally (though the costal long-cells somewhat narrower and shorter); long-cells of similar wall thickness costally and intercostally.

Microhairs absent.

Crown cells absent. Prickles absent (but present marginally as hooks). Macrohairs absent.

Intercostal long-cells variable in shape; varying in shape within single files. Mid-intercostal long-cells somewhat elongated to markedly elongated; usually rectangular (often irregular in form); long-cell walls straight, or slightly undulating; the undulations irregular; the intercostal long-cell walls not conspicuously pitted; outer surfaces of intercostal long-cells not pitted. Papillae absent.

The costal zones all histologically similar; costal short-cells solitary. Costal silica bodies present and perfectly developed; throughout the costal zones; horizontal-crenate.

Intercostal short-cells infrequent; throughout the intercostal zones; solitary. Unsilicified intercostal short-cells square; walls straight. Intercostal silica bodies absent.

Stomata common; present in all the intercostal zones; restricted in distribution within intercostal zones; arranged in definite rows. Stomatal rows in the widest intercostal zones 4; evenly dispersed. Stomata 57-58.5-63 m long; with guard-cells overlapped by the interstomatals. Subsidiaries dome-shaped. The domes of medium height.

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. Width of lamina across a primary vascular bundle 231-265-285 m. Lamina mid-zone in transverse section with ribs both adaxially and abaxially; the adaxial and abaxial ribs opposite one another. Adaxial furrows slight; wide. Adaxial furrows between all the vascular bundles, or between the major vascular bundles only. Adaxial ribs irregular in size; round topped; opposite all vascular bundles, or opposite major vascular bundles only. Vascular bundles in the mid-lamina approximately 60; 1 per rib. Abaxial furrows present between the vascular bundles. Abaxial ribs opposite all the vascular bundles, or opposite major vascular bundles only; smaller than adaxial ribs.

Midrib pronounced in outline; adaxially raised and rounded; prominent abaxially; tissue layout similar to that of other primary vascular bundles. Vascular bundles in the mid-lamina region of the midrib 1. The median vascular bundle with a protoxylem cavity; with an enlarged protoxylem vessel; without sclerosed phloem. Midrib without colourless tissue 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 absent as discrete groups but the epidermis extensively bulliform. Abaxial epidermis of bulliform-like epidermal cells. Abaxial epidermal cell walls not thickened. The cells irregular in shape.

The major vascular bundles interspersed with minor bundles (usually 3 minor bundles between major 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, or without adaxial sclerenchyma; with abaxial sclerenchyma, or without abaxial sclerenchyma; the adaxial sclerenchyma when present, forming strands; the abaxial sclerenchyma when present, forming strands, or forming girders; the smallest vascular bundles lacking sclerenchyma. The adaxial sclerenchyma of the mid-lamina all associated with vascular bundles.

Cytology. 2n = 56.

Common name. Awnless Brome.

Vouchers. Specimens examined morphologically: H.S.McKee 11791: SE. base of Black Mtn, 600 m (A.C.T.); 21.xi.1964; Fl.; CANB.

Material examined anatomically: H.S.McKee 11791 Blk Mtn ACT CANB.

Notes. Economic importance: Cultivated as a fodder crop in parts of east and eastern central Europe (Tutin 1980), but of no economic importance in Australia.

Classification. Triticodae; Bromeae.

Considerable natural variation is said to exist (Tutin 1980), and many varieties have been recognised on minor characters of indumentum distribution or awn development.

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