Beckmannia Host
Named for Johann Beckmann.
Including Buchmannia Nutt, Joachima Ten.
Habit, vegetative morphology. Annual, or perennial; rhizomatous, or caespitose. Culms 30–150 cm high; herbaceous; tuberous (when perennial), or not tuberous. Culm internodes hollow. Leaves non-auriculate. Leaf blades narrow; 4–10 mm wide; flat; without cross venation; rolled in bud; an unfringed membrane; not truncate (acute); 5–10 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets; outbreeding.
Inflorescence. Inflorescence of spicate main branches, or paniculate (the branches sometimes themselves branched); open; non-digitate (branches racemosely arranged); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets secund (the branches unilateral); biseriate.
Female-fertile spikelets. Spikelets 1.5–4 mm long; suborbicular; compressed laterally; falling with the glumes. Rachilla prolonged beyond the uppermost female-fertile floret, or terminated by a female-fertile floret; the rachilla extension when present, with incomplete florets. Hairy callus absent.
Glumes two; more or less equal; long relative to the adjacent lemmas; conspicuously ventricose to not ventricose; pointed; awnless (but mucronate); carinate; similar (herbaceous, navicular, more or less inflated, cross-veined). Lower glume 3 nerved. Upper glume 3 nerved. Spikelets with female-fertile florets only, or with incomplete florets. The incomplete florets when present, distal to the female-fertile florets. The distal incomplete florets 1 (male). Spikelets without proximal incomplete florets.
Female-fertile florets 1, or 2. Lemmas acuminate; cartilaginous; not becoming indurated; entire; pointed; awnless, or mucronate; hairy, or hairless; non-carinate (dorsally rounded); without a germination flap; 5 nerved. Palea present; relatively long; 2-nerved; 2-keeled, or keel-less. Lodicules present; 2; free; membranous; glabrous; toothed, or not toothed; not or scarcely vascularized. Stamens 3. Anthers 0.4–1.8 mm long. Ovary glabrous. Styles free to their bases. Stigmas 2; white.
Fruit, embryo and seedling. Fruit small (1.6–2 mm long); not noticeably compressed. Hilum short. Embryo small. Endosperm liquid in the mature fruit; with lipid. 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; differing markedly in wall thickness costally and intercostally. Mid-intercostal long-cells fusiform; having straight or only gently undulating walls. Microhairs absent. Stomata common. Subsidiaries low dome-shaped, or parallel-sided. Guard-cells overlapped by the interstomatals (mostly, slightly). Intercostal short-cells absent or very rare. Costal short-cells neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies horizontally-elongated crenate/sinuous, or rounded, or crescentic.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma.
Cytology. Chromosome base number, x = 7. 2n = 14 (usually), or 16. 2 ploid. Chromosomes ‘large’.
Taxonomy. Pooideae; Poodae; Aveneae.
Distribution, ecology, phytogeography. 2 species; North Eurasia & North America. Helophytic, or mesophytic; species of open habitats. Meadows, etc.
Holarctic. Boreal, Tethyan, and Madrean. Arctic and Subarctic, Euro-Siberian, Eastern Asian, Atlantic North American, and Rocky Mountains. Mediterranean and Irano-Turanian. European and Siberian. Canadian-Appalachian, Southern Atlantic North American, and Central Grasslands.
Rusts and smuts. Rusts — Puccinia. Taxonomically wide-ranging species: Puccinia graminis, Puccinia coronata, and Puccinia striiformis. Smuts from Tilletiaceae and from Ustilaginaceae. Tilletiaceae — Urocystis. Ustilaginaceae — Ustilago.
Economic importance. Important native pasture species: B. syzigachne.
References, etc. Leaf anatomical: this project.
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).