(classical name, of no significance to these plants). Gentianaceae. Herbs treated either as annuals or biennials or perennials, with flowers of white, lilac, blue or dark purplish blue, cultivated in a very few greenhouses.

Very rarely suffruticose: dwarf or tall and paniculate-branching: leaves sessile, clasping or short-stalked, ovate or lanceolate, mostly 3-5-nerved: flowers small or attaining 2 in. across, rotate, pedicelled or not, in forking cymes; calyx 4-5-parted, the segments keeled, winged or flat and 3-nerved; corolla-lobes 4 or 5, ovate or oblong, twisted; stamens 4 or 5, attached to the throat, with very short filaments, the anthers opening by apical pores that finally enlarge nearly to the base: fruit a globose 2-valved caps. - Species about 30, in tropical and Subtrop. Asia, Malaysia, tropical Africa, Socotra.

Plants of E. affine flower in summer. If specimens in 5-inch pots are desired, sow in March of the same year; for larger specimens, sow in August of the preceding year. The plants must be kept in a cool but not draughty greenhouse or frame in summer, and shaded from fierce sunlight. They usually are given warmhouse conditions.

a. Leaves with stalks often 1/2in. long.

Affine

Balf. stem cylindrical, 1-2 ft. high, much branched from the base: leaves 1-1 1/2 in. long, elhptic-ovate, faintly 3-5-nerved: sepals with a broad wing on the back; corolla 6-9 fines wide; lobes almost rounded. Socotra. B.M. 6824. A.F. 13:1104. Gng. 6:229. R.H. 1883, p. 512. Gt. 32:1108. G.C. II. 21:605.

aa. Leaves nearly or quite stalkless.

B. Corolla-lobes rounded.

Zeylanicum

Roxbg. Annual: stem 4-sided, branched only above: leaves becoming 3 in. long, strongly 3-nerved, elliptic-oblong, acuminate, narrower than in E. affine, and tapering: flowers blue, 1 1/2 in. across, in terminal, leafy corymbs; sepals broadly winged; corolla-lobes obovate, obtuse. Ceylon. B.M. 4423 (sky-blue, with a dash of purple). R.H. 1859, p. 238. J.F. 1:43. H.F. II. 2:60.

bb. Corolla-lobes usually tapering to a point.

Macranthum

Am. (E. zeylanicum variety macranthum). Fig. 1468. stem cylindrical, slightly branched: leaves as in E. zeylanicum, though perhaps more variable from base to summit: flowers purplish blue, 2 in. across. In both species there is a narrow ring of yellow at the mouth, to which the conspicuous clusters of stamens are attached. Ceylon. B.M. 4771 (deep purplish blue). G.C. III. 15:331. R.H. 1911, p. 31. J.H. III. 42:182; 51:259. - The best of the genus. The rich, dark blue is worth striving for.

Fig. 1468. Exacum macranthum ( X 1/3).

Forbesii, Balf. Bushy and shrubby: leaves triangular or ovate-lanceolate, 1 1/4 in. across at base: flowers upwards of 1/2in. across, purple or violet-purple, in terminal racemes, the anthers yellow and prominent. Socotra. G.C. III. 31:93. G. 23:679. G.W. 6, p. 290. G.M. 45:81. - A good plant for intermediate temperature, blooming well in a 6-in. pot. Wilhelm Miller.

L. H. B.†