This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
(E. peliolare, Hort., not Moc. & Sesse). Smoothish or (variety monticolum, Brandegee) sticky-hairy, loosely branched: leaves round-ovate, commonly heart-shaped, shortly taper-pointed, bluntly and rather coarsely toothed: heads slender-stalked, 1/2in. diam.; florets at first white, changing rapidly to pinkish lilac. Low. Calif. G.C. HI. 35:163. - Attractive, rapid-growing, herbaceous, tender. Weak and needing support.
(Conoclinium ianthinum, Morr. Hebeclinium ianthinum, Hook.). Somewhat shrubby, the thickish round stems at first covered with a rusty purplish pubescence: leaves large, ovate, long-stalked, opposite, pointed or blunt (but not heart-shaped) at base, somewhat hairy on both surfaces, serrate: flowers light violet, in a large compound terminal corymb. S. Mex. B.M. 4574. - A luxuriant species with heavy foliage, of easy pot cult, in a warmhouse.
(Ageratum Lasseauxii, Carr. Conoclinium Lasseauxii, Dur.). Habit of Ageratum, densely covered with short glandular hairs: leaves alternate, oblong-lanceolate, narrowed at each end, bluntly toothed: heads in small compact unequally stalked clusters; florets very numerous, at first white, at maturity a vivid rose-color. Temp. S. Amer. R.H. 1870:90. - Intro, to European hort. in 1870. Attractive bedding plant, but apparently rare. Probably not fully hardy though less tender than most of the glasshouse species. Propogation easily and flowers continuously; 1-2 ft. high.
Shrub with lance-shaped, pointed, sharply and unevenly toothed, short-stalked leaves, very unequal involucral scales, and showy reddish lilac heads in large dense flat-topped clusters; florets 5 in each head. In European hort., and said to come from S. Brazil. R.H. 1894:304. Gt. 44, p. 570. G.C. III. 18:265. - Three to 6 ft. tall. Choice, but certainly not the true E. serrulatum, DC, which has much narrower finely and evenly serrulate leaves and 11-12-flowered heads.
(Hebeclinium Urolepis, DC). Robust annual, like a large ageratum: leaves opposite, stalked, round-heartshaped: heads showy, bluish purple; florets numerous (about 75); involucral scales ending in similarly colored hairy appendages. Temp. S. Amer. - Promising species, worthy of trial as a bedding plant.
(E. omphaliaefolium, Kunth & Bouche). Soft-wooded shrub with thick and shining oblong-lanceolate leaves 3-8 in. long: heads loosely pani-cled; involucral scales conspicuously unequal, the outer short and calyx-like, the inner 3-4 times as long; florets white. S. Mex. and Guatemala. Gt. 2, p. 4, t. 39. - From low and moist tropical habitat and presumably very tender. Rare in cultivation and not noticed recently in trade. Needs rich leaf-mold, moist air, and high temperature. Prop, by cuttings. Flowers in March.
(E. ligustrinum, DC E. Morisii, Hort. E. Weinmannianum, Regel & Koern. Many other hort. names, for which see Gt. 22, p. 36). Leaves opposite, elliptic-lanceolate, pinnately veined, the blade somewhat toothed and slightly decurrent in narrow crisped wings upon the short If . - stalk: heads small and few-flowered but very numerous in large round-topped terminal corymb; florets white, but pappus pink-tinged to deep rose. Mex. Gt. 16, p. 260, t. 555, figs. 1-3. Gn. 47, p. 444. G.C. II. 5, p. 53 - Upright shrub rather widely cultivated since about 1830 under a great variety of names, but chiefly as E. Weinmanni-anum.
(E. grandifolium, Regel). Shrubby: leaves opposite, large, thin, triangular-ovate, finely and sharply toothed to the very base, which is somewhat decurrent upon the long If. - stalk: flowers white, in ample lax panicles, almond-scented. Guatemala. Gt. 1; p. 102, t. 12. - Planted out in summer forms a luxuriant shrub, attractive on account of its excellent foliage. Best propogation by cuttings placed in warm bed about the end of August. Winter-bloomer in glasshouse.
(E. adenophorum, Spreng. E. adenonthum, Hort., not DC E. trapezoideum, Kunth.
E. americanum, Hort.). Fig. 1434. Diffuse and often decumbent herb, the slender round branches, petioles, and pedicels finely glandular-puberulent: leaves triangular-ovate or rhombic-ovate, thinnish, slender-stalked, tapef-pointed, coarsely and sometimes unevenly cre-nate-dentate, sparingly puberulent beneath: heads pure white, ageratum-like, in close clusters. Mex. B.R. 1723. - Easy in pot cultivation and not very tender, flowering in late autumn or early winter. Cuttings strike root readily. variety foliis variegatis, Hort. Leaves variegated.
Fig. 1434. Leaves of glasshouse Eupatoriums. a, E. riparium; b, E. vernale; c, E. glandulosum; d, E. glabratum. (X 1/3)
Very viscid like the preceding, probably more tender: leaves similar: heads decidedly larger, 1/2in.. diam. Peru. G.C. III. 7:321. - Recommended as promising and cultivated in a few English conservatories. Apparently not yet in the trade.
(E. triste, Hort., not DC. E. triiste, Hort.). Fig. 1434. Strong herb (slightly woody in the wild), with hairy stems: leaves oblong-ovate, long-stalked, taper-pointed, serrate, finely hairy above, paler and grayish velvety beneath, veiny, 3-5 in. long: flowers bright white, the heads in an ample terminal corymb; involucral scales long, narrow, green. Mex. Gt. 22:750. - Easy in pot cultivation becoming popular for cut-flowers
(Ageratum conspicuum, Hort.). Low, branching half-shrub, very leafy: leaves small, 1/2-1 (rarely 2) in. long, triangular-ovate, sharp-pointed, bluntly few-toothed, thin and nearly glabrous, on slender stalks: heads borne on threadlike pedicels in small or medium-sized flattish clusters. Chile. - Tender greenhouse perennial, but flowering in the open the first year if seeds are sown early. Closely related, if not actually identical was the E. Haageanum, Regel & Koern. introduced into European hort. in the middle of the 19th century (see Gt. 16, p. 260, t. 555, figs. 4-6).