Castellia Tineo.
Habit, vegetative morphology. Annual. Culms 50–100 cm high; herbaceous. Leaves non-auriculate. Sheath margins free. Leaf blades linear; narrow; flat; without cross venation; persistent; an unfringed membrane; truncate; 1–2 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence a single raceme (rarely), or paniculate; open; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets 9–20 mm long; compressed laterally; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets. Hairy callus absent.
Glumes two; relatively large; very unequal to more or less equal; shorter than the adjacent lemmas, or long relative to the adjacent lemmas; hairless; glabrous; pointed, or not pointed; awnless; non-carinate; similar. Lower glume 1–3 nerved. Upper glume 3–5 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. Spikelets without proximal incomplete florets.
Female-fertile florets 3–17. Lemmas less firm than the glumes; not becoming indurated (membranous); entire; awnless; densely tuberculate dorsally; non-carinate; without a germination flap; 5 nerved. Palea present; relatively long; entire to apically notched; 2-nerved; 2-keeled. Lodicules present; 2; free; membranous; glabrous; toothed; not or scarcely vascularized. Stamens 3. Anthers 0.3–0.5 mm long; not penicillate; without an apically prolonged connective. Ovary glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit adhering to lemma and/or palea (to the palea); small, or medium sized (3–4 mm long); compressed dorsiventrally. Hilum long-linear. Embryo small. Endosperm hard; without 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 (costals smaller); of similar wall thickness costally and intercostally. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs absent. Stomata common; 33–36 microns long. Subsidiaries parallel-sided. Guard-cells overlapped by the interstomatals. 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.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; without adaxial palisade. Leaf blade with distinct, prominent adaxial ribs (small, rounded); with the ribs more or less constant in size. Midrib not readily distinguishable; with one bundle only; with colourless mesophyll adaxially. Bulliforms present in discrete, regular adaxial groups; in simple fans. Combined sclerenchyma girders present (in the primaries); forming ‘figures’ (narrow, in the primaries). Sclerenchyma all associated with vascular bundles.
Special diagnostic feature. Lemmas not as in Briza (q.v.).
Cytology. Chromosome base number, x = 7. 2n = 14. 2 ploid.
Taxonomy. Pooideae; Poodae; Poeae.
Distribution, ecology, phytogeography. 1 species; Mediterranean to western Asia. Species of open habitats. Dry places.
Holarctic and Paleotropical. Tethyan. African. Macaronesian, Mediterranean, and Irano-Turanian. Saharo-Sindian.
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).