Northern Prairie Wildlife Research Center
Smooth Ruellia (Ruellia strepens)
- Family: Acanthus (Acanthaceae)
- Flowering: May-September.
- Field Marks: Ruellias have opposite, simple leaves and tubular flowers with 4 stamens. Ruellia strepens differs from all the rest by its lanceolate sepals at least 1/10 inch broad.
- Habitat: Moist woods, around ponds and lakes, along streams.
- Habit: Perennial herbs with fibrous roots.
- Stems: Erect, smooth or branched, slightly hairy, up to 3 feet tall.
- Leaves: Opposite, simple, lanceolate to ovate, pointed at the tip, rounded or tapering to the base, without teeth, smooth or slightly hairy, up to 6 inches long, up to 3 inches broad; leaf stalks up to 1/2 inch long.
- Flowers: 1-3 in the axils of the leaves, blue, subtended by a pair of ovate bracts; each flower up to 3 inches long.
- Sepals: 5, green, united into a very short tube; the lobes lanceolate, about 1/10 inch broad.
- Petals: 5, blue, united to form a funnel-shaped tube; the lobes somewhat unequal in size.
- Stamens: 4, not exserted beyond the corolla.
- Pistils: Ovary superior; stigmas 2-cleft.
- Fruits: Capsules brown, smooth, up to 3/4 inch long; seeds several, brown, 1/10-1/8 inch long.
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