Lobelia, a genus of plants named by Lin-naeus in honor of Matthias Lobel; it is the typo of the order Lobeliaceae, which includes some half dozen other genera besides this. The lobelias are herbs, with milky juice and alternate leaves; the flowers are axillary or in bracted racemes; the calyx tube is adherent to the pod, with a five-cleft limb; corolla mono-petalous, split down its whole length, somewhat two-lipped, the upper lip of two erect lobes, the lower lip spreading and three-cleft; stamens united into a tube by their anthers, and sometimes by their filaments; pod two-celled, many-seeded, opening at the top. This structure with slight modifications runs through the order, which is closely related to the cam-panulacece, scarcely differing from it except in its irregular flowers; the structure of the flowers is much like that in composite, from which they differ in the many-seeded capsule. Acrid and narcotic qualities pervade the whole order, some members of which are eminently poisonous. The genus Lobelia is a large one, and is especially well represented in tropical and subtropical countries; about 15 species are found in the United States east of the Mississippi river.
The most conspicuous of our lobelias, and one of the most noticeable of all our wild flowers, is L. cardinalis, the cardinal flower, which is common in wet places from Canada to Florida; in favorable situations this throws up numerous leafy stems 3 or 4 ft. high, the upper part of winch are flower-bearing, forming a one-sided raceme a foot or more long of large flowers, which are almost unrivalled in the intensity of their scarlet color. Specimens have been found in which the flowers are rose-colored or even white. The cardinal flower is perennial by offsets; i. e., the stems die after flowering; but during the season offshoots are formed which continue the clump if not the individual plant. So showy a plant early attracted attention, and it was introduced into English gardens in 1629, where it has ever since been appreciated as one of the finest perennials; it is rarely seen in our gardens, but its cultivation presents no difficulties if the soil is rich and loamy; in sandy soil it soon runs out. Another showy species, found in similar localities, is the great lobelia, L. syphilitica, so named because the Indians attributed medicinal qualities to it; this is a tall species with large blue flowers, but it is not so showy as the other, the flower spike being leafy.
These species have been hybridized, and with the intermixture of other species have produced a number of fine garden varieties, bearing florists' names, which present a great range of color, and some of them are handsomely variegated. The Indian tobacco, L. inflata, is the most noted of our lobelias, on account of its medicinal activity, and the controversies to which its employment has given rise; it is an annual, 6 to 18 in. high, and much branched, the branches bearing numerous small blue flowers; the pod has an inflated appearance, which is recognized in its specific name, and contains numerous very small seeds. This species has a wide range, and is often common in sandy soil; it is known in some parts of the country as eye-bright. It contains a peculiar, volatile liquid alkaloid, lobelina, and lobelic acid. This herb is a violent emetic, its action being attended with continued and distressing nausea and great general prostration. It has been extensively used by the so-called Thomsonian or botanic practitioners. Probably many deaths have resulted from its incautious or reckless administration. It is comparatively little employed at present, even in the diseases to which it is most suited, that is, affections of the respiratory organs involving a spasmodic element.
It is said to have been used by the American aborigines. It may be given in substance, tincture, or infusion. The dose of the substance is from 1 to 20 grs.; of the tincture, 10 drops to half a drachm. L. cardinalis has been supposed to possess anthelmintic properties. The other native species have but little general interest. The water lobelia (L. Dortmanna) may be found on the borders of ponds, with its leaves, which are tubular, all in a submerged cluster at the root; the slender stem, which projects about a foot above the surface, has a few scattered light blue flowers. - Among the exotic lobelias cultivated for ornament are L. ful-gens and L. splendens, garden plants of similar habit to our cardinal flower, but inferior to it in color; both these are from Mexico, as is L. laxiflora, a tall red- and yellow-flowered greenhouse species; the low, spreading L. eri-nus is from the Cape of Good Hope; its slender stems bear an abundance of blue flowers, or in the various garden forms white and rose-colored flowers; this is an annual, but is readily continued by cuttings, and is a favorite in both greenhouse and border culture; a double variety, probably of this, has recently appeared in Europe. The seeds should be sown on a pot of light rich soil, with a smoothed surface, and not covered, but merely pressed into the soil with some flat surface; the pot should then be covered with a pane of glass to prevent the earth from drying.
Most of the species are readily propagated by cuttings, or by division of the clumps. Among the Lobeliaceae, species of siphocampylos, isotoma, and tupa are cultivated for ornament. - By far the most remarkable of the Lobeliaceae are found on the Hawaiian islands, where they become arborescent. iSix genera, four of them peculiar to the islands, are represented by 37 species. The L. macrostachys has a simple stem 4 to 8 ft. high, crowned with a head of dependent leaves from whose top spring many branches covered with light pink flowers, an exceedingly showy plant. Cyanea superba and the sweet-scented Brighamia insignis are most desirable for cultivation, and the latter plant, although lately discovered, has been raised from seed in England. Most of the tree lobelias have a viscid juice, formerly much used by the natives for bird lime. - On account of their acrid juice, all the plants of the order are to be looked upon with suspicion; unpleasant consequences are said to have resulted from carelessly holding bits of the greenhouse species between the lips.
The activity of L. inflata has already been referred to; isotoma longiflora, of the West Indies, is reputed to be a deadly poison to horses, and the tupa Feuillei of Chili furnishes a dangerous venom.