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Digitaria divaricatissima (R.Br.) Hughes

white-root grass


Info

Subfamily: Panicoideae
Genus etymology: Digitaria = "having fingers" [Latin] refering to the inflorescence structure
Species etymology: divaricatissima = "most widely branched" [Latin] refering to the inflorescence
Photosynthetic type: C4 (warm season)
Nativity: naturalized - accidental
First recorded in Hawaiʻi: 1950

Map

Distribution of Digitaria divaricatissima in Hawaiʻi.

Inflorescence

Digitaria divaricatissima Inflorescence
Digitaria divaricatissima Inflorescence
Digitaria divaricatissima Inflorescence
Digitaria divaricatissima Inflorescence

Plant

Digitaria divaricatissima Plant

Spikelets

Digitaria divaricatissima Spikelets
Digitaria divaricatissima Spikelets
Digitaria divaricatissima Spikelets
Digitaria divaricatissima Spikelets
Digitaria divaricatissima Spikelets
Digitaria divaricatissima Spikelets

Rhizomes

Digitaria divaricatissima Rhizomes
Digitaria divaricatissima Rhizomes
Digitaria divaricatissima Rhizomes
Digitaria divaricatissima Rhizomes

Description

Habit: Perennial; caespitose. Butt sheaths thickened and forming a bulb; pubescent, or villous. Culms erect, or geniculately ascending; 15-60 cm long. Leaf-sheaths pubescent, or hirsute. Ligule an eciliate membrane; 2-3 mm long. Leaf-blades 4-15 cm long; 3-6 mm wide. Leaf-blade surface pubescent. Inflorescences: Inflorescence composed of racemes; deciduous as a whole. Peduncle fracturing. Racemes 4-10; digitate, or borne along a central axis; radiating; unilateral; 8-35 cm long. Central inflorescence axis 0-10 cm long. Rhachis wingless; angular. Spikelet packing distant. Raceme-bases filiform; 10-90 mm long. Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels unequal. Spikelets: Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; acute, or acuminate; 3.75-5 mm long; falling entire. Fertile Spikelets: Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; acute, or acuminate; 3.75-5 mm long; falling entire. Glumes: Glumes two; dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.1-0.25 length of spikelet; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex truncate, or obtuse. Upper glume lanceolate; 1 length of spikelet; membranous; without keels; 3 -veined. Upper glume lateral veins ribbed. Upper glume surface villous; hairy between veins. Upper glume apex acute. Florets: Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous; 5-7 -veined; ribbed; with unevenly spaced veins; villous; acute. Fertile lemma elliptic; 3-4.5 mm long; cartilaginous; much thinner on margins; dark brown; without keel. Lemma margins flat; covering most of palea. Lemma apex acute. Palea cartilaginous. Distribution: Asia-tropical: Malesia. Australasia: Australia. Pacific: north-central.
(Description source: Clayton, W.D., Vorontsova, M.S., Harman, K.T. and Williamson, H. (2006 onwards). GrassBase - The Online World Grass Flora. Available at https://powo.science.kew.org )