Classification Hierarchy
Kingdom Plantae
Subkingdom Tracheophyta
Superdivision Spermatophyta
Division Magnoliophyta
Class Magnoliopsida
Subclass Asteridae
Order Scrophulariales
Family Acanthaceae
Genus Ruellia
Species Ruellia strepens
Smooth petunia

Date: XXXXXXXX XXXX. Location: XXXXXXXXX (map)

BONAP, FNA, ITIS, USDA, VPI

Scientific Name: Ruellia strepens (named in honor of French herbalist Jean Ruelle); strepens—rustling (from the explosive capsules).

Common Name: Smooth petunia, limestone wild petunia

Origin: Native, perennial

Notes: It is infrequent to rare in S.E. IA, usually found in wet environments such as sand/gravel bars along rivers or damp soils along the margins of bodies of water. Compared to its more common relative, R. humilis (humilis means low); R. strepens is taller, younger internodes are less hairy, it prefers wetter habitats, and has broader (2-4 mm wide) calyx lobes.

Additional references: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11.

Field Marks for Identification:

Stems: up to 1 m long; glabrous to minutely hairy (hairs 0.1-0.2 mm long) along 2 longitudinal bands on opposite sides of the stem

Flowers: June; corolla funnelform, pale purple, 4 stamens; 5 calyx lobes 9-20 mm long and 2-4 mm wide, hairy; flowers subtended by hairy lanceolate bracts 10-40 mm long, cleistogamous flowers are sometimes present.

Leaves: larger leaves 7-18 cm long by 3-9 cm wide.

Glossaries of botanical terms: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

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