This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Perennial herbs, or shrubs, with opposite, sometimes verticillate, or rarely alternate leaves, and small bracted flowers, in axillary or terminal, mostly peduncled spikes or heads. Calyx small, membranous, ovoid, campanulate or compressed and 2-winged, 2-4-toothed or 2-4-cleft. Corolla-tube straight or incurved, cylindric, the limb oblique, spreading, somewhat 2- lipped, 4-cleft, the lobes broad, often retuse or eroded. Stamens 4, didynamous, included or exserted; anthers ovate, not appendaged, the sacs nearly parallel. Ovary 2-celled; ovules I in each cavity; style short; stigma oblique or recurved. Fruit dry, with a membranous exocarp, at length separating into 4 nutlets. [In honor of Auguste Lippi, 1678-1703, French naturalist.]
About no species, most abundant in tropical and subtropical America, a few African. Besides the following, which by some authors are separated as a distinct genus (Phyla Lour.), about 6 others occur in the southern United States. Type species: Lippia americana L. Leaves linear-cuneate to spatulate, 2-8-toothed; peduncles little exceeding leaves.
1. L. cuneifolia.
Leaves sharply serrate; peduncles much longer than leaves. Leaves oblong or lanceolate, mostly acute.
2. L. lanceolata.
Leaves spatulate or obovate, mostly obtuse.
3. L. nodiflora.
Zapania cuneifolia Torr. Ann. Lyc. N. Y. 2: 234.
1827. Lippia cuneif olia Steud.; Torr. in Marcy's Rep. 293.
pl. 17. 1853.
Pale, minutely puberulent with forked hairs or glabrous,diffusely branched from the woody base; branches terete, slender, rigid, procumbent, somewhat zigzag, with short erect branchlets at the nodes. Leaves linear-cuneate, sessile, obscurely veined, rigid, 1'-1 1/2' long, 2"-3" wide, with 2-8 sharp teeth above the middle or rarely entire, acutish at the apex; peduncles shorter than or somewhat exceeding the leaves; head at first globose, becoming cylindric and 6"-8' long; bracts cuneate, abruptly acuminate from the truncate or retuse summit; calyx flattened, 2-cleft, the lobes 2-toothed or emarginate; corolla-tube longer than the calyx; fruit oblong.
On plains, South Dakota, Nebraska and Colorado to Texas, Mexico and Arizona. May-Aug.
L. lanceolata Michx. Fl. Bor. Am. 2: 15. 1803.
Green, glabrous, or very sparingly pubescent with forked hairs; stems slender, weak, procumbent or ascending, sometimes rooting at the nodes, simple, or little branched, 1°-2 long. Leaves thin, oblong, ovate, or oblong-lanceolate, pinnately veined, short-petioled, acute or subacute at the apex, sharply serrate to below the middle, narrowed to the somewhat cuneate base, 1'-3' long, 3"- 15" wide; peduncles slender, some or all of them longer than the leaves; heads at first globose, becoming cylindric and about 1/2' long in fruit; bracts acute; calyx flattened, 2-cleft; corolla pale blue, scarcely longer than the calyx; fruit globose.
In moist soil, Ontario to Minnesota, New Jersey, Illinois, Kansas, Florida, Texas and northern Mexico. Also in California. Frog-fruit. June-Aug.
Verbena nodiflora L. Sp. Pl. 20. 1753.
Lippia nodiflora Michx Fl. Bor. Am. 2: 15. 1803.
Minutely and rather densely puberulent with short appressed hairs, creeping, or some of the branches ascending, 1°-3° long. Leaves thickish, spatulate, oblanceolate, or obovate, 6"-2i' long, 3 '-12" wide, mostly obtuse at the apex, narrowed into a long or short cuneate entire base, sharply serrate above the middle; peduncles slender, 1'-6' long, much longer than the leaves; heads at length cylindric and 5"-12" long, 3"-4" thick; calyx flattened, 2-cleft; corolla purple to white.
In wet or moist soil, South Carolina to southern Missouri, Florida and Texas. Also in California, Central America, the West Indies, and apparently the same species in the warmer regions of the Old World. May-Sept.