Disakisperma dubium (Kunth) P.M.Peterson & N.Snow

synonyms: Leptochloa dubia


green sprangletop


Info

Subfamily: Chloridoideae
Genus etymology: Disakisperma = "twice pointed seed" [Greek] refering to the two lobed apex of the grains
Species etymology: dubium = "doubtful" [Latin] refering to ease of confusion with other species
Photosynthetic type: C4 (warm season)
Nativity: naturalized - accidental
First recorded in Hawaiʻi: 1950

Map

 Distribution of Disakisperma dubium in Hawaiʻi.

Inflorescence

Disakisperma dubium Inflorescenceimage credit: Jo_Roberts
Disakisperma dubium Inflorescenceimage credit: Sam_Kieschnick

Plant

Disakisperma dubium Plantimage credit: Jo_Roberts

Spikelets

Disakisperma dubium Spikelets

Description

Plants perennial. Culms (10) 30-110 cm, round or basally compressed, tillering from the basal nodes, not branching from the aerial nodes, mostly glabrous, sometimes pilose basally; internodes solid. Sheaths sometimes with a pilose collar; ligules 1-2 mm, truncate, erose; blades (2)8-35 cm long, 2-8 mm wide, glabrous, strigose, or pilose. Panicles 8-20 cm, with 2-15 subdigitate or racemose branches; secondary panicles often hidden in the lowest leaf sheaths; branches 2-19 cm, ascending to spreading at maturity. Spikelets 4-12 mm, light brown to dark olive green, with 4-13 florets, often widely diverging at anthesis. Glumes narrowly triangular to ovate, acute; lower glumes 2.3-4.8 mm; upper glumes 3.3-6 mm; lemmas 3.5-5 mm, membranous, ovate to obovate, lateral veins glabrous or sericeous, hairs often restricted to the basal portion, sometimes also sericeous on the midvein and between the veins, apices obtuse to truncate, usually emarginate, unawned, sometimes mucronate; paleas ciliate on the margins; anthers 3, 0.3-1.6 mm. Caryopses 1.5-2.3 mm long, 0.9-1 mm wide, strongly dorsally compressed. 2n = 40, 60, 80.
(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/Disakisperma_dubia )