Verbena bracteata Lag. & Rodr.

Creeping Vervain, Bigbract Verbena

Verbena bracteata plant

Family - Verbenaceae

Stems - Prostrate to decumbent, hirsute, herbaceous, multiple from base, to 50cm long, +/-20cm tall, 4-angled, branching.

Verbena bracteata stemStem and node.

Leaves - Opposite, petiolate, typically 3-lobed, hirsute, to +6cm long, +4cm broad. Petioles winged, short. Lobes typically of 2 lateral and one larger terminal, often divided again, serrate-dentate.

Verbena bracteata leavesLeaves.

Inflorescence - Terminal bracteate spikes to 15cm long (tall), elongating in fruit. Flowers subtended by lance-oblong bracts. Bracts to +/-2cm long, 4mm broad, hirsute. Axis (stem) hirsute. Inflorescence diameter typically 1-2 cm.

Verbena bracteata inflorescenceInflorescence.

Flowers - Corolla blue-purple, 5-lobed, salverform, zygomorphic, to 7mm long, 3mm broad at apex, sparsely pubescent externally, pubescent internally. Lobes obtuse at apex. Stamens 4, didynamous, adnate near base of corolla tube, included. Filaments short. Anthers yellow, .2mm long. Style short. Ovary of 2 carpels, 4-lobed. Calyx hirsute, 5-lobed. Tube to 3.5mm long. Lobes linear.

Verbena bracteata flowerCorollas.

Fruits - Nutlets 4, oblong, 2.0-2.5 mm long, enclosed within persistent calyx.

Verbena bracteata inflorescenceImmature fruits.

Flowering - April - October.

Habitat - Disturbed sites, waste ground, pastures, roadsides, railroads.

Origin - Native to U.S.

Other info. - Fortunately, not much close dissection is needed to properly identify this species. The flower parts are very small but the plant can be easily identified by looking at the hirsute stems, flower spikes, and leaves, as well as the tiny flowers. This is somewhat of a pioneering species that is out-competed by larger plants.
This species hybridizes with others of the genus and the resulting offspring have a tendency to morphologically resemble the other parent plants more so than V. bracteata.

Photographs taken in St. Louis, MO., 7-28-03 and 8-15-03 (DETenaglia); also in Washington, Franklin County, MO, 7-15-2018 (SRTurner).