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Descriptions

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

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

Pariana argentea

HABIT Perennial. Culms geniculately ascending; 20–40 cm long. Culm-internodes abbreviated and closely packed at the base; terete; hollow. Culm-nodes with distinct supra-nodal ridge; pallid, or purple; glabrous. Leaves cauline; 7–10 per branch. Leaf-sheaths keeled; glabrous on surface, or pubescent. Leaf-sheath oral hairs setose; spreading; 6–8 mm long. Ligule an eciliate membrane; 0.6–0.7 mm long; scarious; truncate. Leaf-blade base cuneate; with a brief petiole-like connection to sheath; petiole 0.15–0.25 cm long; petiole glabrous. Leaf-blades linear, or lanceolate; 6–12 cm long; 8–16 mm wide; mid-green and glaucous; discolorous with last colour beneath. Leaf-blade surface glabrous. Leaf-blade apex acuminate, or attenuate.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Synflorescence on a separate leafless culm. Inflorescence composed of racemes.

Racemes 1; single; erect; multilateral; 3–4.4 cm long; 10 mm wide; bearing 7 fertile spikelets on each. Rhachis fragile at the nodes. Rhachis internodes linear.

Sexes mixed (in a cluster at each node). Spikelets appressed; subtended by an involucre. Fertile spikelets sessile; 1 in the cluster. Male spikelets pedicelled; 5 in a cluster. Involucre composed of imperfect spikelets; with pedicels forming a cup; oblong. Pedicels fused to each other; united along margins; cuneate; flattened; 3.2–4 mm long; 0.66 length of fertile spikelet; ciliate.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets ovate; laterally compressed; compressed slightly; 5.3–6.1 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume ovate; 1 length of upper glume; chartaceous; 1-keeled. Lower glume primary vein scaberulous. Lower glume apex acute. Upper glume ovate; 1.1 length of adjacent fertile lemma; chartaceous; 1-keeled. Upper glume primary vein scaberulous. Upper glume apex acute.

FLORETS Fertile florets female. Fertile lemma ovate; 4.5–5.2 mm long; coriaceous; without keel. Lemma apex acute. Palea 1 length of lemma; coriaceous; without keels.

FLOWER Lodicules 3; obovate; 1.5 mm long; membranous. Anthers 9–15; 2.6–2.8 mm long; yellow. Filaments united in a tube. Stigmas 2.

MALE Male spikelets distinct from female; 1 flowered; ovate; 7.2–8.3 mm long. Male spikelet glumes 2. Male spikelet lemma 3.5–4 mm long; 2–3 -veined.

DISTRIBUTION South America: Mesoamericana.

NOTES Parianeae. Hollowell & Davidse 1994.

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