Aristida arubensis

HABIT Perennial; caespitose; clumped densely. Basal innovations intravaginal. Culms erect; 20–30 cm long. Culm-internodes smooth. Lateral branches lacking. Leaf-sheaths mostly shorter than adjacent culm internode; smooth. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs. Leaf-blades curved; convolute; 10–20 cm long; 2 mm wide. Leaf-blade surface scabrous; rough adaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle; exserted, or embraced at base by subtending leaf.

Panicle open; linear, or lanceolate; 5–10 cm long; 1 cm wide; contracted about primary branches. Primary panicle branches 1–2 -nate. Panicle axis smooth. Panicle branches scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 11–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.75 mm long; pubescent; acute.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 11–12 mm long; 1.5 length of upper glume; membranous; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 8 mm long; membranous; 1 -veined. Upper glume primary vein smooth. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma linear; subterete; 6.5–7 mm long; coriaceous; without keel; 3 -veined. Lemma midvein scabrous. Lemma surface scaberulous; rough above. Lemma margins convolute; covering most of palea. Lemma apex awned; 3 -awned. Principal lemma awn with 20–25 mm long limb. Lateral lemma awns 17–20 mm long; shorter than principal.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; fusiform; without sulcus. Hilum linear.

DISTRIBUTION South America: Caribbean.

NOTES Aristideae. Henrard 1995.

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