2. Verbena bracteata Lag. & Rodr. (creeping vervain, prostrate vervain)
Pl. 573 g, h;
Map 2685
Plants annual or
perennial, sometimes forming mats. Stems 10–50 cm long, usually spreading to
loosely ascending or spreading with ascending tips, rarely more strongly
ascending, slightly to moderately 4-angled, moderately to densely pubescent
with nonglandular, straight to slightly curved, spreading, often pustular-based
hairs. Leaves sessile or with a winged petiole, the blades 1–5(–7) cm long,
lanceolate to ovate-lanceolate or oblanceolate, tapered to a slender,
nonclasping base, rounded or broadly angled to a bluntly pointed tip, variously
unlobed to pinnately or ternately deeply lobed, the margins also finely to
coarsely toothed, occasionally only above the midpoint, both surfaces
moderately to densely pubescent with loosely ascending, nonglandular, sometimes
pustular-based hairs. Inflorescences usually solitary spikes, 2–20 cm long,
dense (the flowers strongly overlapping), relatively stout, elongating greatly
with age. Bracts 8–15 mm long, 2–4 times as long as the calyx, narrowly
lanceolate to narrowly elliptic. Calyces 3–4 mm long. Corollas 4–6 mm long, the
outer surface glabrous, narrowly funnelform to somewhat trumpet-shaped,
purplish blue, the tube relatively slender, the limb 2–3 mm in diameter.
Nutlets 2.0–2.5 mm long, oblong to narrowly oblong in outline, the inner
surface usually pale and with dense, minute papillae, the outer surface
yellowish brown to reddish brown, with several longitudinal ridges, these with
several cross-ridges above the midpoint. 2n=14, 28. April–October.
Scattered nearly
throughout the state (throughout the U.S.; Canada, Mexico). Banks of streams
and rivers, glades, and disturbed portions of upland prairies; also old fields,
pastures, railroads, roadsides, and open disturbed areas.
This species is
mostly observed in highly disturbed areas, such as along sidewalks, alleys, and
roadsides, sometimes forming mats, especially in sandy soils. It is distinctive
in its long bracts, which are loosely ascending to loosely reflexed (toward the
spike bases). The inflorescences, including the bracts, are mostly 1–2 cm in
diameter. In addition to the putative hybrids listed at the beginning of the
generic treatment, Steyermark (1963) also reported a specimen from Grundy
County deposited at the University of Missouri herbarium (Crookshanks 142)
that he suspected to represent V. bracteata × hastata. However, the late
Harold Moldenke, who was the specialist on hybridization in Verbena,
later redetermined this specimen as V. ×perriana (V. bracteata ×
urticifolia).