Aphanelytrum Hackel
Habit, vegetative morphology. Perennial; stoloniferous and decumbent. Culms herbaceous; scrambling (over rocks and other vegetation). Leaves non-auriculate. Sheath margins joined. Leaf blades narrow; flat; without cross venation; persistent; an unfringed membrane; not truncate; 1 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence few spikeleted; paniculate; open; with capillary branchlets. Inflorescence with axes ending in spikelets. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets unconventional (peculiar, with very long rachilla internodes and tiny glumes); 4.5–7.5 mm long; not noticeably compressed; disarticulating above the glumes; with a distinctly elongated rachilla internode above the glumes and with distinctly elongated rachilla internodes between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; hairless (scabrid); the rachilla extension naked. Hairy callus absent.
Glumes two; minute; very unequal; shorter than the spikelets; shorter than the adjacent lemmas; hairless; awnless; similar. Lower glume 0 nerved. Upper glume 0 nerved. Spikelets with female-fertile florets only.
Female-fertile florets 2–3. Lemmas lanceolate, broadly acuminate; not becoming indurated (membranous); incised; shortly 2 lobed; not deeply cleft; awned. Awns 1; median; from a sinus; non-geniculate; hairless; much shorter than the body of the lemma. Lemmas hairless; carinate; without a germination flap; 5 nerved. Palea present; relatively long; gaping; apically notched; awnless, without apical setae; not indurated; 2-nerved; 2-keeled. Palea keels wingless. Lodicules present; 2; free; membranous; glabrous; not toothed; not or scarcely vascularized. Stamens 3. Anthers 3.5–3.8 mm long; not penicillate; without an apically prolonged connective. Ovary glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit free from both lemma and palea; small, or medium sized (3.5–4); compressed laterally. Hilum short. Embryo small. Endosperm hard. Embryo with an epiblast; without a scutellar tail; with a negligible mesocotyl internode. Embryonic leaf margins meeting.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells markedly different in shape costally and intercostally (costals rectangular); differing markedly in wall thickness costally and intercostally (costals thicker- walled). Mid-intercostal long-cells exaggeratedly fusiform; having straight or only gently undulating walls. Microhairs absent. Stomata absent or very rare. Intercostal short-cells absent or very rare. Costal short-cells neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies horizontally-elongated smooth (sometimes slightly sinuous).
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; without adaxial palisade. Midrib with one bundle only. Sclerenchyma all associated with vascular bundles.
Taxonomy. Pooideae; Poodae; Poeae.
Distribution, ecology, phytogeography. 1 species; western tropical South America. Mesophytic; shade species; glycophytic. In humid montane forest.
Neotropical. Andean.
References, etc. Leaf anatomical: this project.
Illustrations. • Abaxial epidermis of leaf blade. Aphanelytrum procumbens.
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).
