Digitaria spp.
crabgrasses, cottontops, and allies
Worldwide in warm-temperate and tropical regions
Drought Tolerant
Native to North America
Overview
Digitaria spp. is a genus of about 250 to 300 species of annual and perennial grasses in the family Poaceae, known as crabgrasses, finger-grasses, and cottontops. The genus is spread through the warm-temperate and tropical regions of every continent. Most species have slender stems that sprawl across the ground and root where the lower joints touch soil, forming loose mats, while the flowering stems turn upward 6 in to 4 ft (15 cm to 1.2 m) tall. The seed heads are made of several finger-like spikes that radiate from the stem tip like the spokes of a hand, carrying paired spikelets in green to purplish tones; the cottontops add silky white hairs. Several species are aggressive weeds of lawns, crops, and waste ground, above all D. sanguinalis, hairy crabgrass, which germinates in warm soil and seeds heavily before frost. Others are useful plants: D. exilis, fonio, is an ancient cereal grain of West Africa, and D. eriantha, pangola grass, is grown for pasture. Plants grow strongly in heat and poor soil and tolerate hard drought, but most are frost-tender and die back or die outright with cold.
Native Range
The genus is nearly worldwide in warm climates, with centers of diversity in Africa and the warmer Americas. Many species have spread far beyond their original range as crop and lawn weeds.Suggested Uses
Grown chiefly as pasture and hay grasses (D. eriantha) and as the grain crop fonio (D. exilis) in West Africa. In gardens the genus is met mainly as a warm-season weed to manage rather than a plant to set out. Seed of several species feeds birds and small mammals.How to Identify
Appearance
Size & Dimensions
Height6" - 4'
Width/Spread1' - 3'
Bloom Information
Flowering and seeding run through the warm season, from midsummer into autumn until frost. Warm-season annuals can set seed within weeks of germination and produce thousands of seeds per plant. Seed heads dry and shatter to scatter grain as the weather cools.
Detailed Descriptions
Flower Description
green to purplish, sometimes silvery-hairedFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight