Grass Genera of the World

L. Watson and M. J. Dallwitz


Simplicia Kirk

Habit, vegetative morphology. Perennial; caespitose. Culms herbaceous. Culm nodes glabrous. Leaves not basally aggregated; non-auriculate. Leaf blades narrow; without cross venation; persistent; an unfringed membrane; not truncate; 2–3 mm long.

Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.

Inflorescence. Inflorescence paniculate; open, or contracted; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.

Female-fertile spikelets. Spikelets 2.5 mm long; compressed laterally; disarticulating above the glumes. Rachilla prolonged beyond the uppermost female-fertile floret; hairy; the rachilla extension naked.

Glumes two; minute; very unequal to more or less equal; shorter than the spikelets; shorter than the adjacent lemmas (the upper less than 1/4 the length of the floret); pointed; awnless; non-carinate; similar. Lower glume 1 nerved. Upper glume 1–3 nerved. Spikelets with female-fertile florets only; without proximal incomplete florets.

Female-fertile florets 1–2. Lemmas decidedly firmer than the glumes (membranous); not becoming indurated; pointed (acute); awnless, or awned (with or without an awnlet). Awns if present, 1; median; dorsal to apical; from near the top (subapical); non-geniculate. Lemmas hairless (but tuberculate-scabrid); carinate; 3 nerved. Palea present; relatively long; 1-nerved, or 2-nerved; one-keeled. Lodicules present; 2; free; membranous; glabrous; toothed. Stamens 2–3. Anthers not penicillate. Ovary glabrous. Styles free to their bases. Stigmas 2.

Fruit, embryo and seedling. Fruit small; compressed laterally. Hilum short. Embryo not waisted. Endosperm containing compound starch grains. Embryo with an epiblast.

Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells of similar wall thickness costally and intercostally. Mid-intercostal long-cells fusiform; having straight or only gently undulating walls. Microhairs absent. Stomata absent or very rare. Subsidiaries parallel-sided. Intercostal short-cells absent or very rare. Costal silica bodies predominantly horizontally-elongated smooth, or horizontally-elongated crenate/sinuous; not sharp-pointed.

Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma. Leaf blade adaxially flat. Midrib conspicuous; with one bundle only. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’. Sclerenchyma all associated with vascular bundles.

Cytology. Chromosome base number, x = 7. 2n = 28.

Taxonomy. Pooideae; Poodae; Poeae.

Distribution, ecology, phytogeography. 2 species; New Zealand. Species of open habitats. Grassland.

Antarctic. New Zealand.

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).

Index