RTJELUA. XC. ACANTHACE^E. 395 



2. SESAMUM. 



Calyx 5-partcd ; corolla campanulate, 3-cleft, the lower lobe the 

 longest ; stigma lanceolate ; capsule 2-celled, the cells divided by the 

 inflexed edges of the valves. of India. 



S. INDICUM. DC. Oily-seed. Lvs. lanceolate-ovate, lower ones 3-lol>cd, up- 

 per ones undivided, serrate. Native of E. India. Stem erect, about 18' high 

 Leaves alternate, entire. Flowers axillary, subsessile. Corolla pale purple. 

 The seeds yield an excellent oil which will keep several years without injury 

 It is used in cookery for all the purposes of sweet oil. Five pounds of the seed- 

 yirld about one pound of oil. The leaves are emollient. 



OHDEH XC. ACANTHACE^E. ACANTHADS. 



Herbs or shrubs with opposite simple, undivided, exstipulate leaves. 



>V. opposite or alternate, spicate, 3-bracteate, showy. 



Cal. of 5 sepals united more or less, persistent. Cor. 5-Iobed, subequal or bilabiate. 



Ufa. 4, didynamous, or more usually only 2 fertile with 2 rudimentary. 



Ova. 2-celled, with the placenta; parietal, adhering in the axis. Styles unitedr 



Fr. Capsule 2-celled, cells 2 or many-seeded. 



Sds. roundish, supported by hooked, ascending processes of the placenta;, without albumen. 



Genera 105, species 750, chiefly tropical, only a few species ever extending into the United States. Tht ' 

 are mostly mere weeds, but many are highly ornamental. Properties mucilaginous and slightly bitter, bi t 

 of little importance to man. 



^ Genera. 



Stamens 2. Flowers in pedunculate, axillary clusters Dicliprera. 1 



Stamens 4, didynamous. Flowers sessile, axillary liuciiia. 2 



1. DICLIPTERA. Juss. 



Gf. Jif, double. Ka\VTTTrip } a cover; alluding to the 2 remarkable valves. 



Calyx 5-parted, often 2 3-bracteolate ; cor. bilabiate, upper lip 

 emarginate, lower 3-cleft ; fil. 2, each with a double anther ; stig. 1 ; 

 caps, attenuated below, half 2-celled, with 2 elastic valves ; dissepi- 

 ment growing from the centre of each valve ; seeds 4, lenticular. 

 Herbaceous or shrubby. 



D. AMERICANA. Wood. f Justicia pedunculosa. Michx. Dianthera Ame- 

 ricana. Linn.} St. simple; Ivs. linear-lanceolate, acute at each end; 

 spikes capitate, dense, on long, opposite or alternate, axillary peduncles. ij. On 

 sluggish streams, Can. to Ga., W. to Ohio! la. Plummer! 111. Mead. Stern 

 1 3f high, grooved. Leaves opposite, 25' by J 1', wavy, glabrous, contract- 

 ed to a short petiole. Peduncles about as long as the leaves. Flowers pale 

 purple, small. Valves of the capsule recurved elastically when mature, lower 

 half attenuate and abortive; processes of the placentae ascending, supporting 

 the lens-shaped seeds in their grooves. Jl. Aug. 



2. RUELLIA. 



In honor of John Ruelle, physician to Francis I., and botanic author. 



Calyx 5-parted, generally bibracteate at base ; cor. subcampanu 

 Jate with a slender tube and a 5-lobed limb; sta. 4, didynamous, ap 

 proximating by pairs ; caps, attenuated to each end, bursting by elas- 

 tic, tooth-like valves ; seeds few. ^ or h. Fls. axillary and terminal. 

 1. R. STREPENS. (R. hirsuta. Ell. R. ciliosa. Willd.? R. hybrida. Ph. 7 

 R. oblongifolia. MX.?) Hirsute, erect, branched; Ivs. ovate, oval or ob- 

 long, acutish, margin entire, undulate, lower ones briefly petiolate, upper ses- 

 sile ; _/fo. subsessile, axillary, 2 3 together ; cal. segments linear-subulate, his- 

 )id, half as long as the slender tube of the corolla. In dry barrens and prairies, 



funnel-shaped, with a long and slender tube. July. Varies to subglabrous. 

 34 



