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..
Annual or perennial, strongly aromatic and pungent herbs, with small entire or crenulate leaves, and small blue or purple flowers in axillary clusters, these crowded into terminal, leafy-bracted spikes or racemes. Calyx tubular, 13-nerved, villous in the throat, the mouth mostly contracted in fruit, gibbous on the lower side at the base, or nearly terete, 2-lipped, or nearly equally 5-toothed, the upper lip 3-toothed, the lower 2-cleft. Corolla-limb 2-lipped, the upper lip erect, entire, emarginate or 2-lobed, the lower spreading, 3-cleft. Perfect stamens 2, ascending under the upper lip, their anthers 2-celled, the sacs divergent or divaricate. Sterile stamens (staminodia) 2, minute, or none, very rarely anther-bearing. Ovary deeply 4-parted; style 2-cleft at the summit, glabrous. Nutlets ovoid, smooth. [Greek, sweet smell.]
About 15 species, natives of America. Besides the following, some 8 others occur in the southern and southwestern States. Sometimes called Mock Pennyroyal. Type species here taken as Hedeoma pulegioides (L.) Pers.
Teeth of the upper lip of the calyx triangular; leaves serrate; annual.
1. H. pulegioides.
Teeth of both lips of the calyx subulate; leaves entire. Calyx-teeth all nearly equal; annual.
2. H. hispida.
Teeth of the lower lip nearly twice as long as the upper; perennial.
3. H. longiflora.
Melissa pulegioides L. Sp. P1. 593. 1753. Cunila pulegioides L. Sp. P1. Ed. 2, 30. 1762. Hedeoma pulegioides Pers. Syn.- 2: 131. 1807.
Annual; stem very slender, erect, much branched, finely soft-pubescent, 6'-18' high, the branches ascending. Leaves ovate to obovate-oblong, petioled, sparingly serrate, mostly obtuse at the apex and narrowed at the base, glabrous, or sparingly pubescent, thin, 1/2'-1 1/2' long, 2 "-8" wide, the upper smaller; clusters few-flowered, axillary, rather loose; pedicels pubescent, shorter than or equalling the calyx; calyx pubescent, gibbous, oblong-ovoid in fruit, its 3 upper teeth triangular, acute, not exceeding the 2 subulate hispid lower ones; corolla bluish-purple, about 3" long; rudimentary stamens manifest, capitate at the summit, or rarely anther-bearing.
Hedeoma hispida Pursh, Fl. Am. Sept. 414. 1814. Hedeoma hirta Nutt. Gen. 1: 16. 1818.
Annual; stem erect, branched, slender, 3'- 8' high, pubescent, the branches erect-ascending, very leafy and copiously flowered. Leaves linear, entire, firm, sessile, or the lower short-petioled, blunt or subacute at the apex, narrowed at the base, more or less hispid-ciliate but otherwise mostly glabrous, 1/2'-1' long, about 1" wide, the lower much shorter and smaller; clusters axillary, numerous, crowded, several-flowered; pedicels pubescent, shorter than the calyx; bracts subulate, very hispid, about equalling the calyx; calyx oblong, gibbous, hispid, its teeth all subulate, nearly equal in length, upwardly curved in fruit, about one-half as long as the tube, the 2 lower ones somewhat narrower and more hispid than the upper; corolla about 3" long, bluish-purple; sterile stamens rudimentary or none.
On dry plains, Ontario and New York to Saskatchewan, Illinois, Louisiana, Arkansas and Colorado. May-'Aug.
Perennial from a woody base, with an ashy down nearly all over; stems much branched, slender, erect, 6-18 high, the branches ascending. Leaves oblong or linear-oblong, entire, short-petioled or sessile, obtuse at the apex, narrowed at the base, spreading, 5"-10" long, 1"-2 1/2" wide, the lowest shorter; clusters axillary, loosely few-flowered; pedicels puberulent, about one-half as long as the calyx and equalling or longer than the subulate bracts; calyx oblong, hirsute, slightly gibbous, its teeth all subulate, upwardly curved and connivent in fruit, the 2 lower nearly twice as long as the 3 upper; corolla purple, 4"-6" long; sterile stamens rudimentary or none.
In dry soil, South Dakota to Nebraska, Kansas and Texas. Included, in our first edition, in H. Drummondn Benth. of the Southwest. April-Aug.