Daknopholis W. Clayton
Including Chloris boivinii
Habit, vegetative morphology. Prostrate annual; stoloniferous. Culms 10–30 cm high; herbaceous. Culm nodes glabrous. Plants unarmed. Leaves not basally aggregated; non-auriculate. Leaf blades narrow; 2–4 mm wide (and to 20 mm long); flat; without abaxial multicellular glands; without cross venation; persistent; a fringed membrane (short-fringed). Contra-ligule absent.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence of spicate main branches; digitate. Primary inflorescence branches 2–4. Rachides flattened. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets solitary; secund (on unilateral rachides); biseriate; subsessile; imbricate.
Female-fertile spikelets. Spikelets 2 mm long; adaxial; strongly compressed laterally (trigonous); disarticulating above the glumes. Rachilla briefly prolonged beyond the uppermost female-fertile floret; the rachilla extension naked (by contrast with Chloris). Hairy callus present.
Glumes two; relatively large; more or less equal; shorter than the spikelets; shorter than the adjacent lemmas; dorsiventral to the rachis to lateral to the rachis; hairless (glabrous, save for the scabrid keel and margins); awnless; carinate (G1), or non-carinate (G2); very dissimilar (membranous, thin). Lower glume 1 nerved. Upper glume 1 nerved. Spikelets with female-fertile florets only; without proximal incomplete florets.
Female-fertile florets 1. Lemmas similar in texture to the glumes to decidedly firmer than the glumes (membranous to cartilaginous); not becoming indurated; incised; 2 lobed; not deeply cleft (bidentate); awned (usually), or awnless (rarely). Awns 1; median; from a sinus to dorsal; from near the top (just behind the slight notch); non-geniculate; hairless (scabrid); much longer than the body of the lemma; entered by one vein. Lemmas hairless (scabrid marginally and on the nerves); carinate; without a germination flap; 3 nerved. Palea present; relatively long; apically notched; awnless, without apical setae (ciliate on nerves); not indurated (thin); 2-nerved; 2-keeled. Lodicules present; 2; free; fleshy; glabrous; not or scarcely vascularized. Stamens 3. Anthers short; not penicillate; without an apically prolonged connective. Ovary glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit ellipsoid; compressed laterally. Pericarp free.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present; intercostal. Intercostal papillae not over-arching the stomata (or scarcely so); several per cell (a row of large, cylindrical, thick-walled papillae along each long-cell and interstomatal). Long-cells of similar wall thickness costally and intercostally (walls of medium thickness). Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; more or less spherical; clearly two-celled; chloridoid-type (small). Microhair apical cell wall of similar thickness/rigidity to that of the basal cell. Microhair basal cells 9 microns long. Microhair total length/width at septum 2. Microhair apical cell/total length ratio 0.5. Stomata common. Subsidiaries irregularly dome-shaped and triangular. Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells common; not paired (solitary). Intercostal silica bodies absent. Costal short-cells conspicuously in long rows. Costal silica bodies present in alternate cell files of the costal zones; saddle shaped (predominating), or ‘panicoid-type’ (a few).
Transverse section of leaf blade, physiology. Lamina mid-zone in transverse section open.
C4; XyMS+. PCR sheaths of the primary vascular bundles interrupted; interrupted abaxially only. PCR sheath extensions absent. Leaf blade adaxially flat (to slightly adaxially ribbed). Midrib conspicuous (by virtue of a large bulliform group above it); with one bundle only. Bulliforms present in discrete, regular adaxial groups (but inconspicuous save near the centre of the blade); in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (most bundles with minute girders). The lamina margins with fibres.
Taxonomy. Chloridoideae; main chloridoid assemblage.
Distribution, ecology, phytogeography. 1 species; Madagascar and Aldabra I. Species of open habitats; halophytic. Maritime sand.
Paleotropical. African and Madagascan. Sudano-Angolan. Somalo-Ethiopian and South Tropical African.
References, etc. Leaf anatomical: this project.
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).