Dissochondrus (Hillebr.) Kuntze
Habit, vegetative morphology. Perennial; caespitose. Culm nodes hairy. Leaves not basally aggregated; auriculate. Leaf blades broad; pseudopetiolate; without cross venation; disarticulating from the sheaths.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence paniculate; contracted; spicate. Inflorescence axes not ending in spikelets. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets subtended by solitary ‘bristles’, or with ‘involucres’ of ‘bristles’ (these long, sinuous, antrorsely scabrid). The ‘bristles’ persisting on the axis. Spikelets not secund; pedicellate. Pedicel apices cupuliform.
Female-fertile spikelets. Spikelets 3 mm long; compressed dorsiventrally; falling with the glumes. Rachilla terminated by a female-fertile floret. Hairy callus absent.
Glumes two; very unequal; (the longer) long relative to the adjacent lemmas; hairless; scabrous; pointed; awnless; non-carinate; similar. Lower glume 5 nerved. Upper glume 7–9 nerved. Spikelets with female-fertile florets only; without proximal incomplete florets.
Female-fertile florets 2 (i.e. both the florets hermaphrodite). Lemmas decidedly firmer than the glumes; becoming indurated, or not becoming indurated (leathery or crustaceous); entire; pointed; awnless; hairless; non-carinate; having the margins inrolled against the palea; with a clear germination flap; 3–5 nerved. Palea present; relatively long; textured like the lemma; 2-nerved; keel-less. Lodicules present; 2; free; fleshy; glabrous. Stamens 3. Anthers not penicillate; without an apically prolonged connective (but the anthers divaricate). Ovary glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit small.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Mid-intercostal long-cells fusiform; having markedly sinuous walls. Microhairs present (equalling the long-cells in length); panicoid-type; (60–)66–81(–87) microns long; (27–)30–44(–57) microns wide at the septum. Microhair total length/width at septum 6.1–19.3. Microhair apical cells (4.2–)5.4–6 microns long. Microhair apical cell/total length ratio 0.45–0.66. Stomata common; 21–24 microns long. Subsidiaries dome-shaped. Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells common (fairly); in cork/silica-cell pairs. Costal short-cells conspicuously in long rows. Costal silica bodies ‘panicoid-type’; cross shaped, dumb-bell shaped, and nodular (mostly nodular).
Transverse section of leaf blade, physiology. C4. The anatomical organization unconventional. Organization of PCR tissue Arundinella type. XyMS–. Mesophyll with radiate chlorenchyma (slightly); exhibiting ‘circular cells’ (solitaries, small groups and some obviously ‘reduced bundles’). Leaf blade adaxially flat. Midrib with one bundle only to having a conventional arc of bundles (a small bundle under each midrib ‘hinge’). 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. 1 species; Hawaii. Shade species. On slopes.
Paleotropical. Polynesian. Hawaiian.
References, etc. Leaf anatomical: this project.
Special comments. Fruit data wanting.
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).