GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Arthragrostis

HABIT Annual. Culms erect (1/1), or geniculately ascending (1/1); slender (1/1); 17–50.87–80 cm long. Lateral branches sparse (1/1). Ligule a ciliolate membrane. Leaf-blades linear (3), or lanceolate (1). Leaf-blade margins cartilaginous (2/2).

INFLORESCENCE Inflorescence a panicle.

Panicle open. Panicle axis bearing deciduous branches.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels tip cupuliform (2/2).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate (1), or elliptic (1), or ovate; dorsally compressed; 2–4.65–7.5 mm long; falling entire. Rhachilla internodes elongated between glumes (2), or elongated below proximal fertile floret. Rhachilla elongation slender.

GLUMES Glumes shorter than spikelet (3), or reaching apex of florets (1); thinner than fertile lemma. Lower glume lanceolate (1), or elliptic (1), or ovate; membranous; without keels; 3–4 -veined (1), or 5 -veined (2), or 6 -veined (1), or 7 -veined (3). Lower glume surface smooth (3), or scabrous (1); without pits; glabrous (3), or pilose (1). Lower glume apex obtuse (1), or acute (3), or acuminate (1); muticous (3), or mucronate (1), or awned (1). Upper glume lanceolate (2), or elliptic (2), or ovate (1); membranous; without keels; 5–6 -veined (1), or 7 -veined (3), or 8 -veined (1), or 9 -veined (2), or 10–11 -veined (1). Upper glume lateral veins without ribs (2), or ribbed (2). Upper glume surface smooth (3), or scabrous (1); glabrous (3), or pilose (1); with tubercle-based hairs (1/1). Upper glume apex acute (1), or acuminate (3); muticous (3), or awned (2); 1 -awned (2/2).

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate (3), or elliptic (1); membranous; 9 -veined (1/1); without ribs (3), or ribbed (1); acute (1/3), or acuminate (2/3); muticous (3), or awned (2). Fertile lemma elliptic; chartaceous (1), or indurate (3); without keel; wingless; 5–7 -veined (1/1). Lemma surface unwrinkled; without grooves. Lemma margins involute. Lemma apex obtuse (2/2). Palea membranous (2), or chartaceous (1), or indurate (1).

FLOWER Anthers 3 (3/3).

FRUIT Caryopsis with free brittle pericarp (1/1); dorsally compressed (1/1). Embryo 0.5 length of caryopsis. Hilum punctiform (3/3).

DISTRIBUTION Australasia.

Please cite this publication as detailed in How to Cite Version: 27th January 2014.