Grass Genera of the World

L. Watson and M. J. Dallwitz


Anthochloa Nees & Meyen ex Nees

Habit, vegetative morphology. Diminutive perennial; caespitose. Culms 5–10 cm high; herbaceous; unbranched above. Young shoots intravaginal. Leaves not basally aggregated; non-auriculate. Sheath margins free. Leaf blades linear; narrow; 1–3.5 mm wide; flat, or rolled (conduplicate); without cross venation; persistent; an unfringed membrane; truncate; 0.5 mm long.

Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets (but with female and sterile florets distally in the spikelet).

Inflorescence. Inflorescence few spikeleted; paniculate; contracted. Inflorescence with axes ending in spikelets. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; shortly pedicellate.

Female-fertile spikelets. Spikelets 4.5–6.5 mm long; not noticeably compressed (terete); disarticulating above the glumes; disarticulating between the florets; with conventional internode spacings. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets. Hairy callus absent.

Glumes present; two; more or less equal; shorter than the spikelets; shorter than the adjacent lemmas; hairless; not pointed (broadly rounded); awnless; non-carinate; similar (broad, membranous, irregularly dentate). Lower glume 3 nerved. Upper glume 5 nerved. Spikelets with incomplete florets (the lower florets hemaphrodite, female florets above, the uppermost sterile). The incomplete florets distal to the female-fertile florets. The distal incomplete florets clearly specialised and modified in form (the rachilla terminating in a clavate clump of rudiments).

Female-fertile florets 2–4. Lemmas flabelliform, irregularly toothed, often pinkish; similar in texture to the glumes; not becoming indurated; incised (emarginate or split); awnless; hairless; glabrous; non-carinate; without a germination flap; 5 nerved, or 7 nerved. Palea present; relatively long; three lobed, the median lobe itself bilobed; awnless, without apical setae; 2-nerved; 2-keeled. Lodicules present; 2; free; membranous; glabrous; toothed; not or scarcely vascularized. Stamens 3. Ovary glabrous. Styles free to their bases. Stigmas 2.

Fruit, embryo and seedling. Fruit free from both lemma and palea; small (1.5 mm long). Hilum short. Embryo small. Endosperm hard; with lipid; containing compound starch grains. 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 similar in shape costally and intercostally, or markedly different in shape costally and intercostally; of similar wall thickness costally and intercostally. Mid-intercostal long-cells rectangular; 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 predominantly horizontally-elongated smooth (being at the most only slightly sinuate).

Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; without adaxial palisade. Leaf blade adaxially flat. Midrib not readily distinguishable; with one bundle only. Bulliforms not present in discrete, regular adaxial groups; nowhere involved in bulliform-plus-colourless mesophyll arches. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with all the bundles); the girders small. Sclerenchyma all associated with vascular bundles.

Special diagnostic feature. Spikelets with the distal incomplete florets and/or the rachilla apex forming a terminal clavate appendage.

Cytology. 2n = 42.

Taxonomy. Pooideae; Poodae; Poeae.

Distribution, ecology, phytogeography. 2 species; Andes. Species of open habitats. In high mountains.

Holarctic and Neotropical. Madrean. Andean.

References, etc. Leaf anatomical: Metcalfe 1960; this project.

Illustrations. • Abaxial epidermis of leaf blade. Anthochloa lepidula.


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).

Index