Guadua aculeata

HABIT Perennial; caespitose; clumped loosely. Rhizomes elongated; pachymorph. Culms erect, or geniculately ascending, or arching; 1000–1500 cm long; 100–150 mm diam.; woody; with root thorns from the nodes. Culm-internodes terete; with small lumen; distally hispid. Lateral branches dendroid. Branch complement two, or three. Culm-sheaths deciduous; hispid; without auricles; glabrous on shoulders. Culm-sheath ligule ciliolate. Culm-sheath blade triangular; as wide as sheath at base; demarcated but persistent; erect. Leaf-sheaths keeled; striately veined; glabrous on surface; outer margin glabrous, or hairy. Leaf-sheath oral hairs lacking. Leaf-sheath auricles absent. Ligule an eciliate membrane. Collar with external ligule. Leaf-blade base cuneate; with a brief petiole-like connection to sheath; petiole 0.5 cm long; petiole glabrous. Leaf-blades lanceolate, or oblong; 15–19 cm long; 28–30 mm wide. Leaf-blade midrib conspicuous. Leaf-blade venation without cross veins. Leaf-blade surface pilose; sparsely hairy; hairy abaxially. Leaf-blade apex acuminate.

INFLORESCENCE Synflorescence bractiferous; clustered at the nodes; in untidy tufts; lax; with glumaceous subtending bracts; prophyllate below lateral spikelets; leafless between clusters.

Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 2–5 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; compressed slightly; 35–45 mm long; 3–4 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 9–10 mm long; scaberulous.

GLUMES Glumes several; comprising 1–3 gemmiferous bracts; 1–3 empty glumes; persistent; shorter than spikelet. Lower glume ovate; 4–5 mm long; membranous. Lower glume surface asperulous. Lower glume apex obtuse. Upper glume lanceolate, or ovate; 10 mm long. Upper glume surface asperulous. Upper glume apex obtuse.

FLORETS Fertile lemma lanceolate, or ovate; 13 mm long; coriaceous; without keel. Lemma surface scaberulous; glabrous. Lemma apex acute. Palea keels winged; conspicuously winged; ciliolate. Palea surface scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; 5 mm long; membranous; veined; glabrous. Anthers 3; 6 mm long; yellow; anther tip smooth, or penicillate. Stigmas 3.

FRUIT Caryopsis with adherent pericarp; sulcate on hilar side; 7–8 mm long.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Bambuseae. Fl Guatemala 2010.

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