Agropyropsis A. Camus
From Agropyron (another grass genus, q.v.) and the Greek opsis (appearance), alluding to similarity.
Habit, vegetative morphology. Perennial; stoloniferous, or caespitose. Culms 20–60 cm high; herbaceous; unbranched above; 1 noded. Culm nodes hidden by leaf sheaths. Young shoots intravaginal. Leaves mostly basal; non-auriculate; without auricular setae. Leaf blades linear to lanceolate; narrow; about 4 mm wide; rolled; without cross venation; persistent; an unfringed membrane (but ciliolate); truncate; about 0.5–1 mm long. Contra-ligule absent.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence a single spike (tough). Rachides hollowed. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelets solitary; not secund; distichous; sessile; not imbricate.
Female-fertile spikelets. Spikelets 5–9 mm long; compressed laterally to not noticeably compressed; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets. Hairy callus absent. Callus short; blunt (glabrous).
Glumes two; more or less equal; shorter than the spikelets; long relative to the adjacent lemmas; free; lateral to the rachis; hairless; glabrous; fairly not pointed; awnless; non-carinate; similar. Lower glume 3–5 nerved. Upper glume 3–5 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets 1; merely underdeveloped; awnless. Spikelets without proximal incomplete florets.
Female-fertile florets 2–4(–6). Lemmas ovate; less firm than the glumes (somewhat cartilaginous); not becoming indurated; entire; awnless; hairless; glabrous; non-carinate (rounded on the back); without a germination flap; 3 nerved (lower florets), or 5 nerved (upper florets, in the material seen); with the nerves non-confluent. Palea present; relatively long (lanceolate); tightly clasped by the lemma; entire, or apically notched; awnless, without apical setae; textured like the lemma (membranous); 2-nerved; 2-keeled. Palea keels wingless; hairy. Lodicules present; 2; free; membranous; not toothed; not or scarcely vascularized. Stamens 3. Ovary glabrous; with a conspicuous apical appendage (this fleshy, glabrous). Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit free from both lemma and palea; small (2–3 mm long); fusiform; compressed dorsiventrally. Hilum short (shortly linear). Embryo small. Endosperm hard.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells markedly different in shape costally and intercostally (the costals much narrower); of similar wall thickness costally and intercostally (the walls of medium thickness). Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs absent. Stomata common. Subsidiaries non-papillate; high dome-shaped and triangular. Guard-cells slightly overlapped by the interstomatals, or overlapping to flush with the interstomatals. Intercostal short-cells common; consistently in cork/silica-cell pairs; silicified. Intercostal silica bodies rounded. Costal silica bodies horizontally-elongated crenate/sinuous and horizontally-elongated smooth (a mixture of short-crenate forms and potato shapes).
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll without adaxial palisade. Leaf blade with distinct, prominent adaxial ribs; with the ribs more or less constant in size (these broad, flat-topped). Midrib conspicuous (by its large bundle, a fairly prominent, rounded keel and large bulliform ‘hinges’); with one bundle only; without colourless mesophyll adaxially. The lamina symmetrical on either side of the midrib. Bulliforms present in discrete, regular adaxial groups; in simple fans (one at the base of each furrow). All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with all the large bundles); forming ‘figures’ (mostly I’s, the midrib with a large ‘anchor’). Sclerenchyma all associated with vascular bundles (apart from large groups in the blade margins).
Taxonomy. Pooideae; Poodae; Poeae.
Distribution, ecology, phytogeography. 2 species; North Africa, Cape Verde Islands. Halophytic (in damp, saline soils).
Holarctic. Tethyan. Macaronesian, Mediterranean, and Irano-Turanian.
References, etc. Leaf anatomical: this project.
Illustrations. • Spikelet. Agropyropsis lolium. • Spikelet. • Spike. • Caryopsis. • Abaxial epidermis of leaf blade
Cite this publication as: Watson, L., and Dallwitz, M. J. (1992 onwards). ‘Grass Genera of the World: Descriptions, Illustrations, Identification, and Information Retrieval; including Synonyms, Morphology, Anatomy, Physiology, Phytochemistry, Cytology, Classification, Pathogens, World and Local Distribution, and References.’ http://biodiversity.uno.edu/delta/. Version: 18th August 1999. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993 onwards, 1998), and Watson and Dallwitz (1994), and Watson, Dallwitz, and Johnston (1986) should also be cited (see References).
