Arundoclaytonia

HABIT Perennial. Culms erect; 200–300 cm long; firm, or woody; with aerial roots from the nodes. Culm-internodes abbreviated and closely packed at the base. Lateral branches sparse. Ligule a ciliate membrane. Leaf-blade midrib indistinct.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Synflorescence compound; paniculate. Inflorescence comprising only a few spikelets; terminal and axillary; subtended by a spatheole.

Sexes segregated; with male above. Spikelets clustered at each node. Fertile spikelets sessile and pedicelled. Male spikelets sessile and pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; with diminished florets at the apex. Spikelets lanceolate; dorsally compressed; 7–19 mm long; falling entire.

GLUMES Glumes shorter than spikelet. Lower glume ovate; 0.6–0.7 length of upper glume; herbaceous; 1-keeled; 1–3 -veined. Lower glume surface without pits. Lower glume apex acute. Upper glume ovate; 0.4 length of adjacent fertile lemma; herbaceous; without keels; 3–5 -veined. Upper glume lateral veins without cross-veins, or with cross-veins. Upper glume apex obtuse, or acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret ovate; herbaceous; 7–9 -veined; acute. Fertile florets female. Fertile lemma ovate; herbaceous; keeled; wingless; 9–11 -veined. Lemma lateral veins prominent. Lemma surface unwrinkled; without grooves; pilose. Lemma apex acute. Palea tightly convolute around flower; 1.3–2.1 length of lemma; spongy; 9–13 -veined. Palea keels approximate. Apical sterile florets 1 in number; barren; linear, or lanceolate.

FLOWER Lodicules absent. Anthers 2. Stigmas 2.

FRUIT Caryopsis fusiform. Embryo 0.3–0.4 length of caryopsis. Hilum elliptic.

MALE Male spikelets distinct from female; elliptic, or oblong. Male spikelet glumes 2.

DISTRIBUTION South America.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.