Mildbraediochloa Butzin
Habit, vegetative morphology. Perennial. Culms herbaceous. Leaf blades without cross venation.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence paniculate; contracted (‘panicle dense’); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets pedicellate; not in distinct ‘long-and-short’ combinations.
Female-fertile spikelets. Spikelets compressed laterally. Rachilla terminated by a female-fertile floret.
Glumes two; very unequal; long relative to the adjacent lemmas; the upper awned; very dissimilar (G1 short and awnless, G2 bilobed with the median nerve excurrent into an awn). Upper glume obscurely 5 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; paleate; male. The proximal lemmas awned (bilobed, the median nerve excurrent between).
Female-fertile florets 1. Lemmas less firm than the glumes (thinly membranous, by contrast with the firmly membranous G2); not becoming indurated; incised; 2 lobed; awned. Awns 1; median; from a sinus. Palea present. Stigmas 2.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells more or less markedly different in shape costally and intercostally (the costals much narrower); of similar wall thickness costally and intercostally (the walls of medium thickness). Intercostal zones exhibiting many atypical long-cells (mainly in the mid-intercostal regions). Mid-intercostal long-cells rectangular; having markedly sinuous walls (the sinuosity fairly coarse to fine, irregular). Microhairs present; elongated; clearly two-celled; panicoid-type. Stomata common. Subsidiaries non-papillate; low dome-shaped to triangular. Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells fairly common (but not to be confused with small prickles); not paired (seemingly solitary); not obviously silicified. With numerous very small intercostal prickles. Costal short-cells conspicuously in long rows (but the ‘short-cells’ often quite long). Costal silica bodies present and well developed; ‘panicoid-type’; cross shaped and dumb-bell shaped; sharp-pointed and not sharp-pointed.
Transverse section of leaf blade, physiology. C4. The anatomical organization conventional. XyMS+. PCR sheath outlines uneven. PCR sheath extensions absent. Mesophyll with radiate chlorenchyma; traversed by columns of colourless mesophyll cells (these columns infrequent, of small cells, one cell wide). Leaf blade adaxially flat. Midrib not readily distinguishable; with one bundle only. The lamina symmetrical on either side of the midrib. Bulliforms present in discrete, regular adaxial groups; in simple fans and associated with colourless mesophyll cells to form deeply-penetrating fans (the fans very large, usually simple but occasionally with one or two small clourless cells contiguous internally, rarely these forming a linking column). Many of the smallest vascular bundles unaccompanied by sclerenchyma. Combined sclerenchyma girders present (with a few of the primaries); nowhere forming ‘figures’ (the sclerenchyma scanty). Sclerenchyma all associated with vascular bundles.
Taxonomy. Panicoideae; Panicodae; Paniceae.
Distribution, ecology, phytogeography. 1 species; tropical Africa: Annobon Is. On cliffs.
Paleotropical. African. West African Rainforest.
References, etc. Morphological/taxonomic: Butzin 1971. 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).