Digitaria sanguinalis (L.) Scop. |
Common name
Crabgrass
Summer Grass
Derivation
Digitaria Haller, Hist. Stirp. Helv. 2: 244 (1768). From the Latin
digitus (finger), alluding to radiating inflorescence branches.
sanguinalis- from the Latin sanguineus (dull-red) and -alis (pertaining to). Foliage or inflorescence purplish.
Published in
Fl. Carn. 2nd edn, 1: 52 (1772).
Habit
Annual. Stolons absent. Culms decumbent or prostrate, 1060 cm tall, 28-noded,
rooting from lower nodes. Mid-culm internodes glabrous. Mid-culm nodes glabrous
or bearded. Lateral branches sparsely branched. Leaf-sheaths pilose. Leaf-sheath
auricles absent, or present. Ligule an eciliate membrane, 12 mm long.
Leaf-blades flat, 317 cm long, 214 mm wide. Leaf-blade surface smooth
or scabrous, hairy. Leaf-blade margins scabrous.
Inflorescence
Inflorescence digitate or subdigitate, with racemose branches. Racemes 410,
unilateral, 418 cm long. Central inflorescence axis 0.53 cm long.
Rhachis narrowly winged, angular, scabrous on margins. Spikelet packing imbricate.
Spikelets
Spikelets appressed, in pairs. Pedicels 0.30.6 mm long, scabrous. Fertile
spikelets 2-flowered, comprising 1 fertile floret, lower floret sterile, upper
fertile, without rhachilla extension, elliptic, dorsally compressed, acute,
2.53.3 mm long, falling entire. Rhachilla internodes brief up to lowest
fertile floret.
Glumes
Glumes one (the lower absent or obscure) or two, thinner than fertile lemma.
Lower glume 0.20.37 mm long. Upper glume lanceolate, dorsally convex in
profile, 1.21.6 mm long, 3050% of length of spikelet, membranous,
3-nerved. Upper glume surface glabrous or pubescent, hairy between nerves. Upper
glume apex obtuse.
Florets
Basal sterile floret 1, without significant palea. Lemma of lower sterile floret
elliptic, 2.63.2 mm long, 100% of length of spikelet, membranous,
7-nerved, with equidistant nerves, with nerves free at apex, scabrous, rough
on nerves, puberulous, hairy between nerves, acute. Fertile lemma elliptic,
2.43.3 mm long, cartilaginous, much thinner on margins. Lemma surface
striate. Lemma margins flat, covering most of palea. Lemma apex acute, muticous.
Palea cartilaginous. Anthers 3, 0.6 mm long. Hilum elliptic.
Continental Distribution:
Europe, Africa, Temperate Asia, Tropical Asia, Australasia, North America, South
America, Antarctica.
Australian Distribution:
Western Australia, South Australia, Queensland, New South Wales, Victoria, Tasmania.
Western Australia: Drummond, Dale, Menzies, Warren, Roe, Avon. South Australia: Gairdner-Torrens Basin, Flinders Ranges, Eastern, Eyre Peninsula, Northern Lofty, Murray, Yorke Peninsula, Southern Lofty, South-eastern. Queensland: Darling Downs, Warrego, Maranoa. New South Wales: North Coast, Central Coast, South Coast, Northern Tablelands, Central Tablelands, Southern Tablelands, North-Western Slopes, Central-Western Slopes, South-Western Slopes, North-Western Plains, South-Western Plains, South Far Western Plains. Victoria: Murray Mallee, Lowan Mallee, Wimmera, Wannon, Grampians, Riverina, Midlands, Victorian Volcanic Plain, Otway Plain, Eastern Highlands, Gippsland Plains, East Gippsland. Tasmania: North East, Midlands, East Coast.
Classification. (GPWG
2001):
Panicoideae: Paniceae
Notes
Native. A common weed of temperate areas, preferring
loamy disturbed habitats. Flowers mostly Jan.Apr.
Habit (photo)
© Queensland Herbarium
Sharp 52 and Simon
by D.Sharp