(Note: Lower glume absent or very small)

1. Spikelets silky, 4.2-5.9 mm long…D. insularis

1. Spikelets variably pubescent or not, < 4 mm long…2

2. Spikelets ≤ 2 mm long…3

2. Spikelets > 2 mm long…5

3. Inflorescence branches 3-25 cm long. Leaf blades to 40 cm long (but often much smaller). Lower glume present. Spikelet hairs glandular-capitate…D. filiformis

3. Inflorescence branches 2-9 cm long. Leaf blades 1.5-9 cm long. Lower glume absent. Spikelet hairs not glandular-capitate…4

4. Spikelets 1.2-1.5 mm long. Upper (only) glume as long as the spikelet or nearly so. Leaf sheaths glabrous…D. longiflora (Looks like Paspalum conjugatum)

4. Spikelets 1.5-1.8 mm long. Upper (only) glume 1/3 the spikelet length. Leaf sheaths pubescent…D. serotina

5. Spikelets 2.1-2.4 mm long…D. horizontalis

5. Spikelets > 2.5 mm long…6

6. Lower lemma with the veins evenly spaced on the sessile spikelet. Fresh young pedicellate spikelet margins with stiff, protruding bristles distinguished from smaller, thinner, softer hairs; not stoloniferous…D. bicornis

6. Lower lemma with the lateral veins crowded near the margin on the sessile spikelet. Spikelet margins with soft cilia but no stiff protruding bristles. Plants stoloniferous or not. Anthers < 1 mm long. Ligules erose or entire and eciliate. Upper glume (1.2)1.5-2.7 mm…D. ciliaris