A N F Keys
1 Spikes terminal and axillary, flowers helically alternate, subopposite, or opposite decussate; calyx 5-toothed and cylindric; corolla ± radially symmetric; nutlets 4 .. Verbena
1' Spikes axillary, flowers densely whorled, aligned in vertical rows
2 Shrubs with arching, brittle stems; spikes wider than long, flat-topped; calyx weakly 4-toothed or truncate to obscurely 2-lipped; corolla 4−5-lobed, to 14 mm long, with purple or rose-purple lobes; drupe 1-stoned, spheroid, 4−6 × 4−7 mm, purple-black .. Lantana montevidensis [pics]
2' Herbs; spikes length ≥ width, not flat-topped; calyx 2−4-toothed and ± compressed; corolla distinctly 2-lipped, to 3.5 mm long; nutlets 2 .. Phyla
1 Blades < 30 mm long and wider above midpoint, teeth < 5 on one side; basal bractlets of spike opposite decussate, flowers in 8 or 9 vertical rows; calyx shallowly divided .. Phyla nodiflora [pics]
1' Blades 30−60 mm long and typically wider below midpoint, teeth 5 or more per side; basal bractlets of spike in whorls of 5, flowers in 10−13 vertical rows; calyx deeply divided below midpoint .. Phyla lanceolata [pics]
1 Blades 1−2-pinnately dissected with slender segments; inflorescence initially flat-topped, with flowers opposite decussate throughout; calyx > 6.5 mm long; corolla 11−16 mm long .. Verbena pulchella [pics]
1' Blades unlobed or with unequal basal lobes; inflorescence initially not flat-topped, with flowers mostly helically alternate to subopposite; calyx < 6 mm long; corolla < 7 mm long
2 Bractlets at anthesis 2.5−5 mm long increasing 2−3× in fruit and significantly > calyx; corolla 2−2.5 mm across and 4−5 mm long; growing in vernal pool .. Verbena bracteata [pics]
2' Bractlets at anthesis 3−3.5 mm long increasing slightly in fruit and ≤ calyx; corolla 3−4 mm across and 4.5−6.5 mm long; not growing near water .. Verbena lasiostachys var. scabrida [pics]
NB. Verbena scabra Vahl has been recorded from the Los Angeles River, and may be expected within range. This species should be recognized by having a strigose calyx, and the calyx and corolla tend to be shorter than in V. lasiostachys. Verbenas are widely cultivated in southern California, so that other species should be expected where residences or gardens are nearby. Other authorities currently treat species like Verbena pulchella with pinnately compound leaves as belonging instead to a segregate genus Glandularia J. F. Gmelin.
The text of the above keys used with permission from
A Naturalist's Flora of the Santa Monica Mountains and Simi Hills, California
© Copyright
Barry A. Prigge and Arthur C. Gibson
2013