Cleistochloa C.E. Hubb.
Excluding Dimorphochloa
Habit, vegetative morphology. Perennial; caespitose. Culms 30–60 cm high; wiry; branched above. Culm nodes glabrous. Culm internodes hollow. Young shoots usually intravaginal. Leaves not basally aggregated; non-auriculate. Leaf blades narrow; flat, or rolled (rough, with tubercle-based hairs); without cross venation; disarticulating from the sheaths; a fringe of hairs.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets; the exposed spikelets chasmogamous; with hidden cleistogenes. The hidden cleistogenes in the leaf sheaths (borne singly, highly modified).
Inflorescence. Inflorescence few spikeleted; a single raceme (spike-like, terminating culm branches); espatheate. Spikelet-bearing axes persistent. Spikelets solitary; not secund; pedicellate (the pedicels very short). Pedicel apices cupuliform.
Female-fertile spikelets. Spikelets 3.5–4.5 mm long; oblong, or elliptic, or obovate; adaxial; compressed dorsiventrally; biconvex; falling with the glumes. Rachilla terminated by a female-fertile floret. Hairy callus absent.
Glumes present; one per spikelet, or two (the lower minute or absent); (the upper) relatively large; very unequal; shorter than the adjacent lemmas; free; dorsiventral to the rachis; not pointed (rounded); awnless; very dissimilar (G1 minute). Lower glume 0 nerved. Upper glume 5–7 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; epaleate; sterile. The proximal lemmas awnless (hairy on margins and apex); 7 nerved; more or less equalling the female-fertile lemmas; less firm than the female-fertile lemmas to similar in texture to the female-fertile lemmas; not becoming indurated.
Female-fertile florets 1. Lemmas similar to the L1; striate; not becoming indurated; yellow in fruit, or brown in fruit; entire; blunt; awnless; non-carinate; having the margins lying flat on the palea; with a clear germination flap; 5–7 nerved. Palea present; relatively long (margins hairy towards apex); entire (subacuminate); awnless, without apical setae; 2-nerved. Lodicules present; 2; free; fleshy. Stamens 3. Anthers 2.5 mm long; not penicillate. Ovary glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit small; not noticeably compressed. Hilum short. Embryo large. Endosperm containing only simple starch grains. Embryo without an epiblast; with a scutellar tail; with an elongated mesocotyl internode. Embryonic leaf margins overlapping.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells similar in shape costally and intercostally; of similar wall thickness costally and intercostally (fairly thin walled). Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; 48–54 microns long; 7.5–9 microns wide at the septum. Microhair total length/width at septum 5.3–7.2. Microhair apical cells 21–24 microns long. Microhair apical cell/total length ratio 0.44. Stomata common; 33–36 microns long. Subsidiaries dome-shaped (usually), or parallel-sided (rarely). Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells common; in cork/silica-cell pairs; silicified. Costal short-cells conspicuously in long rows. Costal silica bodies ‘panicoid-type’.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with radiate chlorenchyma; Isachne-type (or tending to this), or not Isachne-type. Leaf blade adaxially flat. Midrib not readily distinguishable; with one bundle only. Bulliforms present in discrete, regular adaxial groups; in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’. Sclerenchyma all associated with vascular bundles.
Taxonomy. Panicoideae; Panicodae; Paniceae.
Distribution, ecology, phytogeography. 2 species; Australia. Xerophytic; species of open habitats. Dry sandstone.
Holarctic, Paleotropical, and Australian. Madrean. Indomalesian. Papuan. North and East Australian. Tropical North and East Australian.
References, etc. Morphological/taxonomic: Hubbard 1933b. Leaf anatomical: this project.
Illustrations. • Abaxial epidermis of leaf blade. • 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).
