RUELLiA. XC. ACANTHACE^. 395 



2. SESAMUM. 

 Calyx 5-parted ; corolla campanulate, 3-eleft, the lower lobe the 



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

 iuflexed edges of the valves. — ® of India. 



S. Indicum. DC. Oilii-sced. — Lis. lanceolate-ovMte, lower ones 3-lobed, up- 

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

 Leaves alternate, entire. Flowers axillary, sub.sessile. Corolla pale purple. 

 The seeds yield an excellent oil which will keep several years withoiy injury. 

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

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



Order XC. ACANTHACE.^. Acanthads. 



Herbs or shrubs with opposite, simple, undivided, e.vstipuliite leaves. 



k'Is. oppo:(ite or idleri)ate,fpiciite, 3-bracte:ite, showy. 



Ca!. of5 sepals uiiiterl more or less, persistent. Cor. 5lol)ed, subequal or bilabiate. 



fsVa. 4, diilynamous, or more usually only i fertile with 2 rudimentary. 



Ova. 2-celled, with the placenta parietal, adhering in the a.\is. Spjles united. 



r;-.— Capsule 2-celled. cells 2 or many-seeded. 



Sds. roundish, suiiported by hooked, ascending processes of the placenta?, vv'ithout albumen. 



Genera 103, species 750, chiefly tropical, only a few species ever extending into the United States. They 

 are mostly mere weeds, but miiuy are highly ornamental. Properties mucifaginous and slightly bitter, but 

 of little importance to man. 



Genera. 



stamens 2. Flowers in pedunculate, axillary clusters DicHptera. I 



Stamens 4, didynamous. Flowers sessile, axillary Ruellia. 8 



L DICLIPTERA. Juss. 



Gr. (5if , double, KoXvizTrip, 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. TJusticia pedunculosa. Michx. Dianthera Ame- 

 ricana. Linn.) — 5'^. simple; Ivs. linear-lanceolate, acute at each end; 

 spikes capitate, dense, on long, opposite or alternate, axillary peduncles. — Tj-On 

 sluggish .streams, Can. to Ga., W. to Ohio! la. PlumTner! 111. Mead. Stem 

 1 — 3f high, grooved. Leaves opposite, 2 — 5' 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 placentas 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- 

 late 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'^. Fls. axillct,ry and terminal. 

 1. R. STREPENS. (R. hirsuta. Ell. R. ciliosa. W'dld.? R. hybrida. Ph.7 

 R. oblongifolia. M.c.7) — Hirsute, erect, branched; lis. ovate, oval or ob- 

 long, acuti.sh, margin entire, undulate, lower ones briefly petiolate, upper ses- 

 sile ; fl'i. subsessile, axillary, 2 — 3 together ; cal. se«;ments linear-subulate, his- 

 pid, half as long as the slender tube of the corolla. — In dry barrens and prairies, 

 Ohio ! Ind. ! 111. 1 to Penn. and Southern States. Stem 8—24' high, often sim- 

 ple, clothed with white, bristly hairs. Leaves li — 2i' long,. J — J as wide. Calyx 

 segments 8 — 10" long. Corolla caducous, limb light bluish-purple, 1 — IJ' broad, 

 fimnel-shaped, with a long and slender tube. July. — Varies to subglabroiis, 

 34 



