Fingerhuthia Nees
Including Lasiotrichos Lehm.
Habit, vegetative morphology. Perennial (usually), or annual (rarely, in desert areas); caespitose. Culms 5–117 cm high; herbaceous; unbranched above. Culm nodes glabrous. Culm internodes hollow. Plants unarmed. Young shoots intravaginal. Leaves mostly basal; non-auriculate. Sheath margins free. Leaf blades long linear; narrow; 2–5 mm wide; flat, or folded; without abaxial multicellular glands; without cross venation; persistent; a fringe of hairs; 0.1–0.7 mm long (and the base of the blade sometimes hairy above the ligule).
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets of sexually distinct forms on the same plant, or all alike in sexuality; hermaphrodite, or hermaphrodite and sterile (the lowest sometimes barren). Apomictic (peculiarly so), or reproducing sexually (?).
Inflorescence. Inflorescence a single raceme, or paniculate (to 12 cm long); densely contracted; more or less ovoid to spicate; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets solitary; not secund; pedicellate; imbricate.
Female-fertile spikelets. Spikelets 4–7 mm long; strongly compressed laterally; falling with the glumes (disarticulating from persistent pedicels); not disarticulating between the florets; with conventional internode spacings. Rachilla prolonged beyond the uppermost female-fertile floret; tough; the rachilla extension with incomplete florets. Callus of spikelet blunt.
Glumes two; more or less equal; exceeding the spikelets; long relative to the adjacent lemmas; hairy (with straight hairs on the keels and margins); pointed; awned, or awnless (shortly awned or mucronate); carinate (ciliate on keel); similar (narrow, folded, thin). Lower glume 1 nerved. Upper glume 1 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets 1–3; merely underdeveloped (male or rudimentary). Spikelets without proximal incomplete florets.
Female-fertile florets 1. Lemmas similar in texture to the glumes to decidedly firmer than the glumes (rather firmly membranous); not becoming indurated; entire; pointed, or blunt; mucronate (via the excurrent median nerve); hairy (long-ciliate on the keels and margins), or hairless (F. sesleriformis); carinate; without a germination flap; (3–)5 nerved, or 7 nerved; with the nerves confluent towards the tip. Palea present; relatively long; apically notched; awnless, without apical setae; textured like the lemma; basally indurated to not indurated; 2-nerved; 2-keeled. Palea keels wingless. Lodicules present; 2; free; fleshy; glabrous. Stamens 3. Anthers 2–2.5 mm long; without an apically prolonged connective. Ovary glabrous. Styles free to their bases. Stigmas 2; white.
Fruit, embryo and seedling. Fruit free from both lemma and palea; ellipsoid; somewhat compressed laterally. Embryo with an epiblast; with a scutellar tail; with an elongated mesocotyl internode. Embryonic leaf margins overlapping.
Ovule, embryology. Micropyle oblique. Outer integument extensive, being absent only from the micropylar region; two cells thick at the micropylar margin. Inner integument continuous, the micropyle constricted; thickened around the micropyle. Synergids not haustorial; without large, globular starch grains.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells similar in shape costally and intercostally (but the costals smaller); of similar wall thickness costally and intercostally (quite thick walled). Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; elongated; clearly two-celled; chloridoid-type to Enneapogon-type (suggestive of a small version of the latter). Microhair apical cell wall thinner than that of the basal cell but not tending to collapse to of similar thickness/rigidity to that of the basal cell. Microhairs 52.5–67 microns long. Microhair basal cells 33–36 microns long. Microhairs 9–10.5 microns wide at the septum. Microhair total length/width at septum 5.1–6.3. Microhair apical cells 18–24 microns long. Microhair apical cell/total length ratio 0.34–0.44. Stomata common; 24–27 microns long. Subsidiaries triangular. Guard-cells overlapped by the interstomatals (very slightly). Intercostal short-cells common; in cork/silica-cell pairs (and some solitary); silicified. Intercostal silica bodies imperfectly developed; rounded, or saddle shaped, or crescentic, or cubical. Costal short-cells predominantly paired. Costal silica bodies present throughout the costal zones; saddle shaped (a round version, predominating everywhere), or rounded (a few, merging with the saddles), or crescentic (a few, plus a few more or less cubical).
Transverse section of leaf blade, physiology. Lamina mid-zone in transverse section open.
C4; XyMS+. PCR sheath outlines even. PCR sheaths of the primary vascular bundles interrupted; interrupted both abaxially and adaxially. PCR sheath extensions absent. PCR cell chloroplasts centripetal. Mesophyll with radiate chlorenchyma; traversed by columns of colourless mesophyll cells. Leaf blade ‘nodular’ in section to adaxially flat; with the ribs more or less constant in size (somewhat larger over large bundles). Midrib not readily distinguishable; with one bundle only. Bulliforms present in discrete, regular adaxial groups; associated with colourless mesophyll cells to form deeply-penetrating fans (these incorporated in the traversing columns of colourless cells). All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with the primaries); forming ‘figures’ (anchors, but only in the primaries: the smaller bundles with strands only). Sclerenchyma all associated with vascular bundles. The lamina margins with fibres (large).
Cytology. Chromosome base number, x = 10. 2n = 20 and 40. 2 and 4 ploid.
Taxonomy. Chloridoideae; main chloridoid assemblage.
Distribution, ecology, phytogeography. 2 species; Southern Africa, Afghanistan and Arabia. Helophytic, or mesophytic, or xerophytic; species of open habitats; glycophytic.
Holarctic, Paleotropical, and Cape. Tethyan. African. Irano-Turanian. Saharo-Sindian and Sudano-Angolan. South Tropical African and Kalaharian.
Rusts and smuts. Smuts from Ustilaginaceae. Ustilaginaceae — Ustilago.
References, etc. Leaf anatomical: Metcalfe 1960; this project.
Special comments. Fruit data wanting.
Illustrations. • General aspect
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).
