Jansenella Bor
Habit, vegetative morphology. Annual. Culms herbaceous; unbranched above. The shoots not aromatic. Leaves not basally aggregated. Leaf blades lanceolate; narrow; 3–7 mm wide (to about 3.5 cm long); slightly cordate; flat; without cross venation; an unfringed membrane.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence paniculate; contracted; spicate; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets paired (usually), or in triplets (rarely); not secund.
Female-fertile spikelets. Spikelets 6–9 mm long; purplish; compressed laterally; disarticulating above the glumes. Rachilla terminated by a female-fertile floret. Hairy callus present. Callus short; blunt.
Glumes two; very unequal; (the upper) long relative to the adjacent lemmas; hairless; pointed; awned (aristulate, the points 1–2 mm long), or awnless. Lower glume 3 nerved. Upper glume 5 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets (or the L1 occasionally hermaphrodite). The proximal incomplete florets when present, 1; paleate. Palea of the proximal incomplete florets fully developed (two keeled, narrowly two winged). The proximal incomplete florets male, or sterile (or even female). The proximal lemmas awned (with a short, dorsal capillary awn); 5–9 nerved; decidedly exceeding the female-fertile lemmas (similar to G2); less firm than the female-fertile lemmas (membranous, leathery); not becoming indurated.
Female-fertile florets 1(–2). Lemmas decidedly firmer than the glumes; becoming leathery; incised; 2 lobed; deeply cleft; awned. Awns 1, or 3; median, or median and lateral (the two lobes aristulate); the median different in form from the laterals (if laterals considered present); from a sinus; geniculate. The lateral awns shorter than the median. Lemmas hairy. The hairs in tufts (these thick, near the margins at the bases of the lobes); in transverse rows (transversely bearded with brown hairs in the lower half). Lemmas non-carinate; 7–9 nerved. Palea present; relatively long; apically notched; 2-nerved; 2-keeled. Palea keels winged (and with peculiar unicellular, turgid hairs between the keels). Lodicules present; 2; free; glabrous. Stamens 3. Anthers not penicillate; without an apically prolonged connective. Ovary glabrous. Stigmas 2.
Fruit, embryo and seedling. Fruit small (1.3 mm long). Hilum short. Embryo large.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Microhairs present; panicoid-type. Costal silica bodies ‘panicoid-type’; dumb-bell shaped.
Transverse section of leaf blade, physiology. Supposedly C3 (but needing further study: certainly the anatomical drawings of Türpe (1970) show neither ‘circular cells’ nor the expected small bundles); XyMS– (from Türpe’s detailed drawings, which if accurate reveal this as the only known C3 XyMS- combination). Mesophyll with radiate chlorenchyma. Leaf blade adaxially flat. Midrib not readily distinguishable.
Cytology. 2n = 20.
Taxonomy. Panicoideae; Panicodae; Arundinelleae.
Distribution, ecology, phytogeography. 1 species; India, Burma. Mesophytic. Moist places in hills.
Paleotropical. Indomalesian. Indian.
References, etc. Leaf anatomical: Metcalfe 1960, Türpe 1970.
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).