24 RUBIACE^. Bouvardia. 



Mag. t. 1854; Lindl. Bot. Keg. xxvi. t. 37. B. Jacquini, irOK. 1. c. 385; DC. Prodr. iv. 

 365; Gray,Pl. Wriglit. ii. 67. B. quutcrnifoiia, DC. 1. c. ? B. coccinea, Liuk, Euum. i. 139. 

 B. ternijUiu, Schlec;ht. in Liun. xxvi. 98. B. splendcns, Graham in Bot. Mag. t. 3781. Ixora 

 ternifolia, Cav. Ic. iv. t. 305. /. Americana, Jacq. Hort. Schoenb. iii. t. 257. Iloustonia coc- 

 cinea, Andr. Bot. Rep. t. 106. — Eocky ground, S. Arizona, &c., Wrirjlit, Thurher, Rothrock, 

 Prin</Ip, Lemmon. (Mex.) 



Var. angUStifolia. Cinereous-pubcruleut or liirtellous : leaves smaller (8 to 18 lines 

 long), subsessile, less veiny, from obloug-lanceolate to almost linear. — B. hirtella & B. angus- 

 tlfolia, HBK. 1. c. 384. B. hirtella, Gray, PI. AVriglit. i. 80, ii. 67. — S. Vv^ Texas to Arizona, 

 Wright, &c. (Mex.) 



4. HOUSTCNIA, Gronov. (Named by Gronovius, as says Linnaeus, in 

 memory of Dr. Win. Houston, who died in Jamaica in 1733.) — Low herbs, 

 or one or two suffruticulose (Atlantic-American and Mexican), with heterogone- 

 dimorphous flowers ; the corolla blue or purple to white, upper face of lobes 

 sometimes puberulous. — L. Hort. Cliff. 35, & Gen. ed. 1 (1737) ; Juss. Gen. 197 ; 

 Gray, Proc. Am. Acad. iv. 313, & Man. ed. 5, 212 ; Benth. & Hook. Gen. ii. 60. 

 Hedyotis in part (Wight & Arn.), Torr. & Gray, Fl. ii. 36. {Macrohoustonia, 

 Gray, Proc. Am. Acad. iv. 314, is a peculiar group of Mexican species, between 

 this genus and Bouvardia.^ 



§ 1. EuHOUSTONiA. Low herbs, comparatively small-flowered : leaves not 

 rigid : capsule more or less didymous or cmarginate, sometimes septicidal as well 

 as loculicidal across the broad summit. 



* Delicate species, inch to span high: corolla salverform: anthers or stigmas included or only par- 

 tially emerging from the throat: peduncles single, elongated and erect in fruit: seeds rather few 

 acetabidiform with a deep hilar cavity: stipules a transverse membrane milling the petioles, 

 mostly entire or truncate and naked. 



•f— Perennial by delicate filiform creeping rootstocks or creeping stems: peduncles filiform, inch or 

 two long: seeds subglobose with orifice of the deep hilar cavity circular. 



H. CSerulea, L. (Bluets of the Canadians, Innocence.) Perennial by slender rootstocks, 

 forming small tufts, erect, a span or more liigli, glabrous, and with lower leaves hispidulous : 

 these spatulate to obovate and short-petioled ; upper small and nearly sessile: corolla violet- 

 blue to lilac, varying to white, with yellowish eye ; tube (2 or 3 lines long) much exceeding 

 calyx-lobes, longer than or equalled by those of corolla : capsule obcordate-depressed, half 

 free. — Spec. i. 105 (Moris. Hist. sect. 15, t. 4, f. 1 ; Pluk. Aim. & Maut. t. 97, f. 9) ; Sims, 

 Bot. Mag. t. 370 ; Barton, PI. Am. SeptT t. 34, f. 1. H. pusiUa, Gniel. Syst. i. 236 ? H. Lin- 

 na:i, var. elatior, Miclix. Fl. i. 85. //. serpyllijblia, Graham, Bot. Mag. t. 2822, from habitat 

 and figure, but corolla-tube too short. Hedijotis ccerulea, Hook. Fl. i. 286 ; Torr. & Gray, 

 Fl. ii. 38. II. gentianoides, Endl. Iconogr. t. 89. Oldcnlandia ccerulea, Gray, Man. ed. 2, 174. 

 — Low and grassy grounds, Canada to Michigan and the upper country of Georgia and 

 Alabama; fl. early spring. 



H. serpyllifolia, Michx. Perennial by prostrate extensively creeping and rooting fili- 

 form stems, and some subterranean ones, glabrous or slightly and minutely hispidulous 

 below : leaves orbicular to ovate or ovatc-spatulate (2 to 4 lines long) and abruptly petioled, 

 or upper ones on flowering stems oblong and nearly sessile : corolla deep violet-blue, rather 

 larger than in H. ca:ridea. — Fl i. 85; Pursh, Fl. i. 106. 77. tenella, Pursh, 1. c. Hedijotis 

 serpyllifolia, Torr. & Gray, Fl. ii. 39. Oldcnlandia serpyllifolia. Gray, Mau. ed. 2; Chapm. 

 Fl. 180: — Along streamlets and on mountain-tops in the Alleghanies, from Virginia to 

 Tenn. and S. Carolina ; flowering through early summer. 



■•~ "i^ Winter-annuals, branching from the simple root, glabrous or obscurelv scabrous: pedun- 

 cles a quarter-inch to at length sometimes an inch long: capsule somewhat didymous, less than 

 half free: mature seeds generally as of the preceding. 



H. pdtens, Fi,l. An inch to at length a span high, with ascending branches and erect pe- 

 duncles : leaves spatulate to ovate: corolla much smaller than that of II. ccvridea; the tube 

 twice the length of the calyx-lobes and more or less longer than its lobes, violet-blue or pur- 



