Germainia Bal. & Poitr.
Including Balansochloa Kuntze, Sclerandrium Stapf & Hubbard
Excluding Chumsriella
Habit, vegetative morphology. Annual, or perennial; stoloniferous (rarely), or caespitose. Culms 6–100 cm high; herbaceous. Culm internodes hollow (or variable?). Leaves mostly basal, or not basally aggregated; non-auriculate. Leaf blades narrow; without cross venation; an unfringed membrane, or a fringed membrane (?); truncate; 0.5–2 mm long.
Reproductive organization. Plants monoecious with all the fertile spikelets unisexual; without hermaphrodite florets. The spikelets of sexually distinct forms on the same plant; female-only and male-only, or female-only, male-only, and sterile. The male and female-fertile spikelets mixed in the inflorescence. The spikelets overtly heteromorphic (the sessile and involucral spikelets awnless, with dissimilar glumes); in both homogamous and heterogamous combinations (each raceme with one or two basal, homogamous pairs).
Inflorescence. Inflorescence peduncled, often long-exserted, solitary, capitate to elongate and consisting of few- to many-jointed racemes; digitate (the racemes appressed or divergent); espatheate (but the peduncle sometimes enclosed in the uppermost sheath); not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes very much reduced (to a peduncle, with two sessile spikelets and a pedicellate one on a short axis), or ‘racemes’; solitary, or paired to clustered (1–2(-6) racemes, fused at their bases); tardily disarticulating; finally disarticulating at the joints. Spikelets associated with bractiform involucres (the basal, sessile, homogamous spikelets forming an involucre round the heterogamous pairs); paired; sessile and pedicellate; consistently in ‘long-and-short’ combinations; in pedicellate/sessile combinations. Pedicels of the ‘pedicellate’ spikelets free of the rachis. The ‘shorter’ spikelets male-only, or sterile (when ‘involucral’). The ‘longer’ spikelets female-only.
Female-sterile spikelets. The sessile spikelet larger, male or barren, dorsally compressed. Male spikelets with 2 stamens in the upper floret. Rachilla of male spikelets terminated by a male floret. The male spikelets with glumes; with proximal incomplete florets; 2 floreted. The lemmas awnless. Male florets 2; (the upper floret) 2 staminate.
Female-fertile spikelets. Spikelets somewhat compressed dorsiventrally (subterete); falling with the glumes. Rachilla terminated by a female-fertile floret. Hairy callus present. The callus hairs brown (to yellow). Callus pointed, or blunt.
Glumes two; more or less equal; long relative to the adjacent lemmas; hairy, or hairless; pointed, or not pointed; awnless; non-carinate; similar (papery, narrow, blunt). Lower glume not two-keeled; not pitted; relatively smooth; 0–5 nerved. Upper glume 0–3 nerved. Spikelets with female-fertile florets only, or with incomplete florets (G. truncatiglumis). The incomplete florets when present, proximal to the female-fertile florets (sometimes suppressed). The proximal incomplete florets when present, 1; sterile. The proximal lemmas awnless.
Female-fertile florets 1. Lemmas without apical teeth, reduced to the membranous or stipitate awn-base; less firm than the glumes; entire; awned. Awns 1; median; apical; geniculate; hairy. Lemmas hairless; 1 nerved. Palea present; relatively long; entire, or apically notched, or deeply bifid; awnless, without apical setae; not indurated (hyaline); nerveless. Lodicules absent. Stamens 0. Ovary glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit free from both lemma and palea; small (0.6–3.2 mm long). Hilum short. Embryo large.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present. Intercostal papillae over-arching the stomata. Mid-intercostal long-cells having markedly sinuous walls. Microhairs present; panicoid-type. Stomata common. Subsidiaries papillate; triangular. Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells common. Costal short-cells neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies ‘panicoid-type’.
Transverse section of leaf blade, physiology. C4; XyMS–. Mesophyll with radiate chlorenchyma. Leaf blade adaxially flat. Midrib conspicuous; having a conventional arc of bundles; with colourless mesophyll adaxially. Bulliforms present in discrete, regular adaxial groups; in simple fans, or associated with colourless mesophyll cells to form deeply-penetrating fans. Many of the smallest vascular bundles unaccompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’. Sclerenchyma all associated with vascular bundles.
Cytology. 2n = 14.
Taxonomy. Panicoideae; Andropogonodae; Andropogoneae; Andropogoninae.
Distribution, ecology, phytogeography. 8 species; Asia, Malesia & North Australia.
Paleotropical and Australian. Indomalesian. Indo-Chinese, Malesian, and Papuan. North and East Australian. Tropical North and East Australian.
References, etc. Morphological/taxonomic: Chaianan 1972. Leaf anatomical: this project.
Illustrations. • General aspect, spikelet
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).
