Sporobolus indicus (L.) R.Br.

synonyms: Sporobolus berteroanus, Sporobolus poiretii


West Indian dropseed, smutgrass


Info

Subfamily: Chloridoideae
Genus etymology: Sporobolus = "seed thrower" referring to the seed being ejected from the pericarp
Species etymology: indicus = refering to the West Indies (Carribean)
Photosynthetic type: C4 (warm season)
Nativity: naturalized - intentional
First recorded in Hawaiʻi: 1912

Map

 Distribution of Sporobolus indicus in Hawaiʻi.

Inflorescence

Sporobolus indicus Inflorescence
Sporobolus indicus Inflorescence
Sporobolus indicus Inflorescence
Sporobolus indicus Inflorescence
Sporobolus indicus Inflorescence

Plant

Sporobolus indicus Plant
Sporobolus indicus Plant
Sporobolus indicus Plant

Spikelets

Sporobolus indicus Spikelets
Sporobolus indicus Spikelets
Sporobolus indicus Spikelets
Sporobolus indicus Spikelets
Sporobolus indicus Spikelets
Sporobolus indicus Spikelets
Sporobolus indicus Spikelets

Description

Plants perennial; cespitose, with tough fibrous roots, not rhizomatous. Culms 30-100 (120) cm. Sheaths usually keeled below, glabrous; ligules 0.2-0.5 mm; blades (6)10-30(50) cm long, 1-5 mm wide, flat, glabrous on both surfaces. Panicles 20-35(50) cm long, 0.3-2.2(3) cm wide, contracted, narrow, sometimes included in the uppermost sheath; primary branches 0.4-2.5(5) cm, appressed or spreading to 40° from the rachis, as long or longer than the adjacent internodes; secondary branches appressed, spikelet-bearing to near the base; pulvini glabrous; pedicels 0.1-1.8 mm, appressed. Spikelets 2-2.6(2.7) mm, plumbeous to light brownish. Glumes subequal, ovate or obovate, membranous; lower glumes 0.5-1 mm, often without midveins; upper glumes 0.8-1.6 mm, 1/2 - 2/3 as long as the florets, acute to obtuse, entire; lemmas 1.8-2.6(2.7) mm, ovate, membranous, glabrous, acute or obtuse; paleas 1.9-2.4 mm, ovate, membranous, glabrous; anthers 3, 0.5-1.1 mm, white, sometimes purple-tinged. Fruits 1-1.2 mm, quadrangular, laterally compressed, reddish-brown, truncate. 2n = 18, 24, 36.
(Description source: Barkworth, M.E., Capels, K.M., Long, S. & Piep, M.B. (eds.) 2003. Flora of North America, north of Mexico. Volume 25. Magnoliophyta: Commelinidae (in part): Poaceae, Part 2. Oxford University Press, New York. 783 pp. http://floranorthamerica.org/Sporobolus_indicus )