Henrardia C.E. Hubb.
Named for Dutch agrostologist J.Th. Henrard.
Habit, vegetative morphology. Annual. Culms herbaceous. Leaves auriculate, or non-auriculate. Leaf blades linear; narrow; 1–3 mm wide; flat, or rolled (convolute); without cross venation; an unfringed membrane; unevenly truncate; 0.2–0.5 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence a single spike (with embedded spikelets). Rachides hollowed. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes disarticulating; disarticulating at the joints. Spikelets solitary; not secund; distichous.
Female-fertile spikelets. Spikelets 7–10 mm long; not noticeably compressed; falling with the glumes. Rachilla prolonged beyond the uppermost female-fertile floret. Hairy callus absent.
Glumes two; more or less equal; exceeding the spikelets; long relative to the adjacent lemmas; displaced (side by side, both abaxial); without conspicuous tufts or rows of hairs; pointed, or not pointed (acute to obtuse); not subulate; awnless; non-carinate; similar (asymmetrical). Lower glume 3–7 nerved. Upper glume 5–9 nerved. Spikelets with female-fertile florets only, or with incomplete florets. The incomplete florets distal to the female-fertile florets. Spikelets without proximal incomplete florets.
Female-fertile florets 1–2. Lemmas acute; less firm than the glumes (very soft); not becoming indurated; entire; pointed; awnless; hairy; non-carinate; without a germination flap; 3–5 nerved. Palea present; relatively long; 2-nerved; 2-keeled. Lodicules present; 2; free; membranous; ciliate; toothed, or not toothed; not or scarcely vascularized. Stamens 3. Anthers 0.5–2.2 mm long. Ovary hairy. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit adhering to lemma and/or palea (slightly); medium sized (4–6.2 mm long); shallowly longitudinally grooved; compressed dorsiventrally; with hairs confined to a terminal tuft. Hilum long-linear. Embryo large to small (up to 1/3 the length of the caryopsis). Endosperm containing only simple starch grains. Embryo with an epiblast.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells similar in shape costally and intercostally; differing markedly in wall thickness costally and intercostally (costals with thicker walls). Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs absent. Stomata common; 60–63 microns long. Subsidiaries low dome-shaped, or parallel-sided. Guard-cells overlapped by the interstomatals (mostly, slightly). Intercostal short-cells absent or very rare. Prickle/macrohair bases abundant. Costal short-cells neither distinctly grouped into long rows nor predominantly paired (mostly solitary). Costal silica bodies horizontally-elongated crenate/sinuous (some almost qualifying as ‘nodular’), or rounded (a few).
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll without adaxial palisade. Leaf blade with distinct, prominent adaxial ribs; with the ribs more or less constant in size. 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 the furrows); in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (large bundles only); forming ‘figures’. Sclerenchyma all associated with vascular bundles (except for massive groups in the blade margins).
Cytology. Chromosome base number, x = 7. 2n = 14. 2 ploid. Haplomic genome content O. Chromosomes ‘large’.
Taxonomy. Pooideae; Triticodae; Triticeae.
Distribution, ecology, phytogeography. 2 species; southwest & Central Asia. Species of open habitats. Dry slopes.
Holarctic. Boreal and Tethyan. Euro-Siberian. Mediterranean and Irano-Turanian. European.
References, etc. Morphological/taxonomic: Löve 1984. 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).