GrassBase - The Online World Grass Flora


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

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

Arundoclaytonia dissimilis

HABIT Perennial; caespitose; clumped densely. Culms erect; 200–300 cm long; firm, or woody; with aerial roots from the nodes (lower part). Culm-internodes abbreviated and closely packed at the base; solid (lower part). Lateral branches sparse. Leaves basal and cauline; spiral. Leaf-sheaths longer than adjacent culm internode (densely); glabrous on surface. Ligule a ciliate membrane; 0.9–2.1 mm long. Leaf-blades 45–80 cm long; 8–16 mm wide. Leaf-blade midrib indistinct. Leaf-blade margins ciliate; hairy at base. Leaf-blade apex hooded.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Synflorescence compound; paniculate. Inflorescence comprising only a few spikelets; comprising 7–20 fertile 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. Pedicels 0.5 mm long.

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

GLUMES Glumes dissimilar; shorter than spikelet. Lower glume ovate; 1.5–2 mm long; 0.6–0.7 length of upper glume; herbaceous; 1-keeled; 1–3 -veined. Lower glume apex acute. Upper glume ovate; 2.2–3.5 mm long; 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; 3–5.1 mm long; 0.3–0.4 length of spikelet; herbaceous; 7–9 -veined; acute. Fertile florets female. Fertile lemma ovate; 5.7–8 mm long; herbaceous; keeled; 9–11 -veined. Lemma lateral veins prominent. Lemma surface pilose; hairy below (at base). Lemma hairs 1–1.5 mm long. Lemma apex acute. Palea lanceolate; tightly convolute around flower; falcate; 1.3–2.1 length of lemma; spongy (lower part); 9–13 -veined. Palea keels approximate (resulting in a shallow groove). Apical sterile florets distinct from fertile; 1 in number; barren; linear to lanceolate; 0.1–4 mm long.

FLOWER Lodicules absent. Anthers 2; 2.2–2.9 mm long. Filaments free. Stigmas 2.

FRUIT Caryopsis fusiform; 6–7 mm long. Embryo 0.3–0.4 length of caryopsis. Hilum elliptic.

MALE Male spikelets distinct from female; 3–9 flowered; without rhachilla extension, or with rudimentary apical florets; elliptic, or oblong; 3.5–7.5 mm long. Male spikelet glumes 2. Male spikelet lemma 3–9 -veined.

DISTRIBUTION South America: Brazil.

NOTES Steyermarkochloeae. TB.

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