Perennial, often forming broad tussocks. Stems 40–80 cm. Leaves: blades 2–4 mm wide; throat with long hairs. Inflorescence a diffuse panicle 10–40 cm long, not much enclosed in leaf sheath. Spikelets 2–2.5 mm long. Lemmas 1.5–2.5 mm long (Lavin in
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Alkali Dropseed -
Sporobolus airoides*Habit: Perennial.
*Panicle: Diffuse, greater than 4 centimeters long, and about as long as wide
and usually fully exerted from the leaf sheath.
*Stem: Base is decumbent.
*Spikelets: 2-2.5 mm long.
Sand Dropseed -
Sporobolus cryptandrus*Habit: Perennial.
*Panicle: Contracted (appressed), greater than 4 centimeters long, and much longer than wide
and enclosed in an arcuate leaf sheath.
*Stem: Base is erect.
*Spikelets: 2.5 mm or shorter. Both glumes are not as long or longer than the lemma.
Small Dropseed -
Sporobolus neglectus, SOC
*Habit: Annual.
*Panicle: Contracted (narrow), less than 4 cm long,
and usually partially enclosed by the leaf sheath.
*Spikelets: 2-3 mm long.
Tall Dropseed -
Sporobolus compositus, SOC
*Habit: Perennial.
*Panicle: Contracted (appressed), but much longer than wide
and usually partially enclosed in the leaf sheath.
*Stem: Base is erect.
*Spikelets: 3 mm or more long. Both glumes are not as long or longer than the lemma.
Prairie Dropseed -
Sporobolus heterolepis, not documented in Montana
*Habit: Perennial.
*Panicle: Open, greater than 4 centimeters long, and much longer than wide
and usually entirely exerted from the leaf sheath.
*Spikelets: At least one of the glumes is as long or longer than the lemma.
On moderately alkaline soils and moderately disturbed open dry vegetation, including road and trailsides (Lavin in
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
