Cinna L.
Cinna: an old Greek name for a grass.
Including Abola Adans., Blyttia Fries
Habit, vegetative morphology. Perennial (tall, of wet habitats); rhizomatous, or caespitose (laxly, or the culms solitary). Culms (20–)50–200(–220) cm high; herbaceous; tuberous (somewhat, in C. arundinacea), or not tuberous. Culm nodes glabrous (or somewhat scaberulous). Culm internodes hollow. Leaves non-auriculate. Sheath margins free. Sheaths glabrous. Leaf blades linear; broad to narrow; 1–20 mm wide (to 40 cm long); flat (with scabrous margins); without cross venation; an unfringed membrane; 2–10(–12) mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence paniculate (with numerous spikelets); open; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets (1.9–)2–6(–7.5) mm long; compressed laterally; falling with the glumes. Rachilla prolonged beyond the uppermost female-fertile floret (usually, as a stub or bristle), or terminated by a female-fertile floret (rarely); the rachilla extension with incomplete florets (usually), or naked. Hairy callus absent. Callus short.
Glumes present; two; relatively large; more or less equal (the lower sometimes somewhat shorter); long relative to the adjacent lemmas (a little shorter to a little longer); free; hairless; glabrous to scabrous (smooth to scaberulous); pointed (acute or acuminate); awnless (sometimes mucronate); carinate; similar (thinly membranous, the margins hyaline). Lower glume 1 nerved. Upper glume 1 nerved, or 3 nerved. Spikelets with female-fertile florets only (usually), or with incomplete florets (very rarely). The incomplete florets when present, distal to the female-fertile florets. The distal incomplete florets 1; merely underdeveloped. Spikelets without proximal incomplete florets.
Female-fertile florets 1 (nearly always, though the second floret when present is said to be occasionally ‘fertile’). Lemmas similar to the glumes; similar in texture to the glumes to decidedly firmer than the glumes (firmly membranous); not becoming indurated; entire, or incised; when entire pointed, or blunt; awnless, or mucronate, or awned. Awns when present, 1; dorsal; from near the top (or subterminal); non-geniculate; straight; much shorter than the body of the lemma; entered by one vein. Lemmas hairless; carinate; without a germination flap; 3 nerved, or 5 nerved. Palea present; relatively long; thinner than the lemma (hyaline); 1-nerved, or 2-nerved (one veined in C. arundinacea, ostensibly so in the others by apposition of the two veins); one-keeled (literally so in C. arundinacea, ostensibly so by close apposition in the rest). Lodicules present; 2; free; membranous; ciliate; toothed, or not toothed (rarely); not or scarcely vascularized. Stamens 1, or 2. Anthers (0.4–)0.6–1.2(–2.6) mm long. Ovary glabrous. Styles free to their bases. Stigmas 2; white.
Fruit, embryo and seedling. Fruit free from both lemma and palea; small (about 2.5 mm long); yellowish brown; compressed laterally. Hilum short. Embryo small. Endosperm liquid in the mature fruit, or 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 markedly different in shape costally and intercostally; of similar wall thickness costally and intercostally. Mid-intercostal long-cells fusiform; having straight or only gently undulating walls. Microhairs absent. Stomata common; (30–)33–36(–38) microns long. Subsidiaries parallel-sided. Guard-cells overlapped by the interstomatals. Intercostal short-cells absent or very rare. Prickles abundant. Costal short-cells neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies horizontally-elongated crenate/sinuous, or horizontally-elongated smooth.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma.
Cytology. Chromosome base number, x = 7. 2n = 28. 4 ploid. Chromosomes ‘large’.
Taxonomy. Pooideae; Poodae; Aveneae.
Distribution, ecology, phytogeography. 3–4 species; Temperate Eurasia, North & South America. Helophytic, or mesophytic; shade species; glycophytic.
Holarctic and Neotropical. Boreal. Arctic and Subarctic, Euro-Siberian, Eastern Asian, Atlantic North American, and Rocky Mountains. Caribbean, Venezuela and Surinam, and Andean. European and Siberian. Canadian-Appalachian and Southern Atlantic North American.
Rusts and smuts. Rusts — Puccinia. Taxonomically wide-ranging species: Puccinia graminis, Puccinia coronata, and Puccinia recondita.
References, etc. Morphological/taxonomic: Brandenburg, Blackwell and Thieret 1991. 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).