212 



GENTIANE^E. XLIII. SEB.EA. XLIV. EXACUM. 



mous ; leaves sessile, ovate, 3-nerved ; flowers quinquefid ; seg- 

 ments of calyx acuminated, with simple keels on the back, about 

 equal to the segments of corolla in length. Q. G. Native of 

 Van Diemen's Land, and of New South Wales. E'xacum 

 ov&tum, Labill. nov. holl. 1. p. 38. t. 52. Corolla red. ? 

 Oyate-leaved Sebfea. Fl. Aug. Clt. 1820. PI. \ foot. 



8 S. AMBIGUA (Cham, in Linnaea, 6. p. 346.) stem fastigiately 

 cymose, dichotomous ; leaves broad-ovate, rather fleshy ; flowers 

 quadrifid ; stamens exserted ; calyx obconical, with diaphanous, 

 obtuse, rounded, toothed segments. . G. Native of the 

 Cape of Good Hope. 



Var. a, gnicilis (Cham. 1. c.) outer branches of cyme evolute. 

 Var. ft, crdssa (Cham. 1. c.) outer branches of cyme con- 

 tracted ; flowers glomerate. 

 Ambiguous Sebsea. PI. \ foot. 



9 S. PUSILLA (Ecklon, mss. Cham, in Linnaea, 6. p. 346.) 

 flowers quinquefid ; stamens inclosed ; calyx cylindrical, with 

 narrow-lanceolate, keeled, acute segments, which are shorter 

 than the tube of the corolla. O- G. Native of the Cape of 

 Good Hope. This species comes nearest to S. ovata ; but dif- 

 fers from it in the tube of the corolla, being longer in the in- 

 closed stamens, and whole habit. 



Small Sebaea. PI. small. 



Cult. These are elegant plants while in blossom. They 

 should be treated like other tender annuals, by being reared on 

 a hot .bed, and afterwards planted out into a warm, sheltered 

 border, about the end of May. 



XLIV. E'XACUM (from ex, out ; and ago, to drive ; expels 

 poison.) Spreng. gen. 1. p. 8. E'xacum species, Lin. gen. 141. 

 Juss. gen. 142. Centaurium, Plukn. mant. t. 343. f. 3. 



LIN. SYST. Tetrandria, Monogynia. Calyx campanulate, 

 4-cleft ; segments winged on the back. Corolla salver-shaped, 

 or sub-rotate, with a globose or ventricose tube, and a 4-cleft 

 limb. Stamens 4, declinate ; filaments terete ; anthers long, 

 somewhat tetragonal, emarginate at the base, erect, dehiscing by 

 2 pores at the apex. Style filiform, declinate, flexuous ; stigma 

 undivided, clavate, furnished with minutely papillose furrows on 

 all sides. Capsule globose, crustaceous, 2-celled, with a septici- 

 dal dehiscence ; placentas 2, adnate to a double dissepiment, 

 thick. Seeds very minute, scrobiculate. Erect, branched, an- 

 nual herbs. Leaves opposite, decussate, sessile, 3-5-nerved. 

 Flowers terminal and axillary. 



1 E. SE'SSILE (Lin. spec. 163.) stem erect, tetragonal, 

 simple, dichotomous at top ; flowers solitary, from the forks 

 of the stem, and tops of the branches ; leaves sessile, ovate- 

 cordate, obtuse, fleshy; capsule drooping. Q, S. Native of 

 the East Indies. Flowers larger than the leaves. 



Sessile-Rovrered Exacum. PL | foot. ? 



2 E. PUNCTA'TUM (Lin. syst. 155. suppl. 124.) leaves nearly 

 sessile, oblong, 3-nerved, dotted like Hyperkum ; stamens ex- 

 serted. O- S. Native of the East Indies. Corolla bluish. 

 Stamens yellow. 



Dotted-\ea.ved Exacum. PI. J to 1 foot. 



3 E. BI'COLOB (Roxb. fl. ind. 1. p. 413.) erect; stem and 

 branches tetragonal : angles a little winged ; leaves sessile, 

 ovate, 5 -nerved ; flowers axillary, solitary, on short pedicels; 

 anthers erect. Q. S. Native of Cuttack, in the East Indies. 

 Root almost simple. Leaves variable in size ; floral ones small 

 and narrow. Corollas large, white, having the segments tipped 

 with blue. 



Trvo-coloured-Rov/ered Exacum. PI. 1 to 2 feet. 



4 E. TERAGONUM (Roxb. 1. c. Wall. pi. rar. asiat. 3. p. 47. t. 

 276.) stem simple, erect, tetragonal ; leaves sessile, ovate-lan- 

 ceolate, 5-nerved ; flowers numerous, terminal ; stamens and 



style declinate. Q. S. Native of Bengal, where it is called 

 Koochuri ; Silhet, Nipaul, Katnaon, &c. E. Chulesium, Ham. 

 herb. Leaves 2-4 inches long. Flowers large, of a most beau- 

 tiful blue colour. Calycine segments dagger-shaped. Segments 

 of corolla acute. Anthers linear. This is a most elegant, robust 

 plant. 



7'e<rrt j ow!a/-stemmed Exacum. Fl. July, Sept. Clt. 1820. 

 PI. 3 to 4 feet. 



5 E. STYLOSUM (Wall. cat. no. 4355.) glabrous ; stem tetra- 

 gonal ; leaves ovate-lanceolate, acute, 3-nerved ; peduncles 

 axillary and terminal, corymbose ; style longer than the sta- 

 mens ; segments of corolla obtuse. 0. S. Native of the East 

 Indies, about Prome. 



Long-styled Exacum. PI. 2 to 3 feet. 



6 E. TE'RES (Wall, in Roxb. fl. ind. 1. p. 414.) stem and 

 branches terete ; leaves lanceolate, acuminated, tapering at the 

 base, nearly sessile, 3-nerved ; peduncles opposite, 3-flowered, 

 forming a terminal corymb ; segments of corolla lanceolate, acu- 

 minated. Q. S. Native of Silhet, and Lower Nipaul. Leaves 

 3-4 inches long, and ^ an inch broad in the middle. Flowers 

 dark blue, large. Habit of the preceding. 



Terete-stemmed Exacum. PI. 2 feet. 



7 E. ZEYLA'NICUM (Roxb. fl. ind. 1. p. 414.) erect; stem 

 and branches tetragonal : angles slightly winged : leaves nearly 

 sessile, ovate-lanceolate, acuminated, 3-nerved; racemes termi- 

 nal and axillary, forming an expanded, terminal, corymb-formed 

 panicle ; flowers pentamerous ; calyx with 5 broad, membranous 

 wings, with subulate points. . H. Native of Ceylon, and 

 the Neelgherries. Chironia trinerva, Lin. fl. zeyl. p. 90. Willd. 

 spec. 1. p. 1065. Burm. zeyl. p. 145. t. 67. Leaves 1-3 

 inches long. Peduncles and pedicels tetragonal. Segments of 

 calyx furnished with a broad, membranous wing on the back of 

 each. Tube of corolla gibbous. Limb of corolla of 5 obovate, 

 mucronate, beautiful, violet-coloured divisions. Anthers linear, 

 straight, and hard, with 2 pores at the apex, and also opening 

 on the sides. 



Ceylon Exacum. PI. 1 to 2 feet. 



8 E. GRANDIFLORUM (Wall. cat. no. 4358.) stem tetragonal ; 

 leaves ovate-lanceolate to lanceolate, acute, 3-5-nerved ; pedun- 

 cles axillary and terminal, trichotomous, or 3-flowered, corym- 

 bose. S. Native of the East Indies, at Courtallum. 

 Flowers large ; segments of corolla ovate-oblong, acute. 



Great-flowered Exacum. PI. 1 to 2 feet. 



9 E. PEDUNCULA'TUM (Lin. spec. 163. Vahl, symb. 1. p. 15.) 

 erect ; stem [with 1-2 pairs of opposite branches, then di- 

 chotomous, slightly tetragonal ; leaves nearly sessile, oblong- 

 lanceolate, obtuse, 3-nerved ; segments of calyx membranously 

 winged on the back; stamens exserted ; style declinate. Q. S. 

 Native of Ceylon. E. carinatum, Roxb. fl. ind. 1. p. 415. Se- 

 bae'a carinata, Spreng. syst. 1. p. 426. Root branched. Flowers 

 terminal, numerous, pretty large, yellow, collected in dichoto- 

 mous corymbs, with a single, long, pedicellate flower in each 

 fork. Filaments inserted on a membranous rim, round the in- 

 side of the mouth of the tube. Anthers erect, opening at the 

 sides, yellow. Perhaps a species of Sebee'a. 



Peduncled Exacum. PI. -|- foot. 



10 E. PTERA'NTHUM (Wall. cat. no. 4360.) stem and branches 

 tetragonal ; leaves elliptic-oblong, tapering to both ends, 3-5- 

 nerved ; flowers pedicellate, dichotomously cymose : with a 

 flower in each fork ; alternate wings of calyx the largest. . 

 H. Native of Tavoy. 



Wing-flowered Exacum. PI. 1 foot. 



HE. HAMILTONII; stem 4-winged ; leaves elliptic-oblong, 

 acute, 5-nerved ; flowers terminal, corymbose ; segments of 

 calyx ovate, acuminated, each furnished with a membranous 

 wing on the back. . G. Native of Nipaul, where it is called 



