ACANTHACE^. 451 



— Leaves opposite, exstipulate, vsually entire or crenulate-repand ; the pair often unequal : 

 herbaceous parts usually lineolate <J>y adnate down) ; flowers usually supported hy hmo- 

 teoles I seeds mostly compressed. 



This Order is mucilaginous; it aifords slightly bitter or aromatic drugs {Dianthera). 

 Fixed oil is extracted from the seeds of Sesamum : this genus, though anomalous, approaches 

 Acanthacea by Thunbergia. 



TaiBE I. ECHMATJCANTHEJE, iis.— Dissepiment of the capsule 2-partite. Seeds 

 supported by retinacula (except in Elytraria). 



Series 1. Buellideee, T.Anders. MS. — Corolla-lobes sinistrorsely contorted. Filaments 

 connected in pairs at the base. 



1, ELYTRARIA, V, 



Calyx 5-4-partite, unequal. Corolla small, 2-lipped. Fertile stamens 2 ! anther-cells 

 parallel. Capsule 8-seeded : segments of the dissepiment adnate to the valves : retinacula 

 none. — Herbs ; superior leaves transformed into decussate, appressed scales, inferior rosulate; 

 flowers spicate ; bracts and bracteoles scarious. 



1. E. tridentata, F. Anilual; rosulate leaves lanceolate-oblong, scales subulate-lanceo- ^ 

 late ; bracts subulate, oiliate, awned, superiol" often emarginate. — E. froudosa, fasciculata, ^ 

 and ramosa, Kth. E. apargiifolia, Ns.' — Variable in the scaly branches all from the base ( 

 or axillary, the down, the spikes simple or ternate, the bracts acuminate or awned from the ' 

 emarginate top. — Hab. Trinidad !, Lockh., on rocky soil ; [New Mexico 1 to Buenos Ayres !]. 



2. RUELLIA, L. 



,. (Bipteracanthus and Cryphiacantbus, iVi.) 



Calyx S-partite or deeply 5-fid, snbequal. Corolla infundibular : limb subequal. Stamens 

 didynamous, included \ anther-cells parallel. Capsule 4-24(-2) -seeded : segments of the 

 dissepiment adnate to the valves, often at length reduced above the seeds. — Herbs or shnibs ; 

 flowers axillary, racemose, or in axillary cymes. 



Sect. 1. Gymnacanthus, Oerst. Calyx deeply h-fid. Capsule not compressed, i-8-seeded 

 above the solid base : retinacula denticulate at the summit. Flowery axillary, sessile, 

 ebracteolate. 

 j/'2. R. geminiflora, Kth. Herbaceous or sufiiatescent, haii-y or glabrescent; leaves 

 lanceolate, lanceolate-oblong, or ovaie, suisessile ; flowers 2-1 in the axil ; calyx'segments ( 

 linear-acuminate ; corolla-tube enlarged from the middle ; capsule ovoid, pubescent, 4-8eeded 

 above the base.— Bipteracanthus, Ns-. .'—Usually l'-2' high ; calyx 4"'-5"', purple corolla 

 l"-li" long. 



[a. Down spreading; leaves ovate-oblong or oblong, l"-li" long.] 

 j8. angustifolia, Down spreading ; leaves lanceolate, li"-2i" long. — D. geminiflorus, 

 var. angustifolius, Ns^ ! 



y. canescens. Down pubescent, short ; leaves oblong-lanceolate, 1" long. — ^Bipteracan- 

 thus canescens, Ns. I 



Hab. Jamaica!, Marf., Pd., Jfils., March, in savannahs (y) ; Trinidad!, Lockh-.i Cr. (fi) ; 

 [Cuba ! and Mexico ! to Peru 1 and Brazil 1]. 



Sect. 2. ApHEAdMiA, Ns.-^Calyx deeply S-'parfite: Capsule- suicompressed, 16'4(-2)- 

 seeded: retinacula subulate.-— Cymes spreading, axillary: 2 bracts below the lateral 

 flowers. 



3. R. pamculata, Xi. Shrubby, glandular ; leaves ovate-lanceolate, cuneate at the (1 

 petioled base ; cymes in a divaricate panicle ; calyx-segments linear-flliform : bracts lanceo- 

 late ; corolla-tube enlarged above the middle ; capsule oblong-linear, laterally subcompressed, 

 8-12-8eeded above the base: seeds smooth.— «. iS.lOO./. 2.— Dipteracanthus, Ns.l—W- 

 3' high, trailing ; calyx 4'"-, blue corolla 1" long.- Hab. Jamaica !, Macf., March, m dry 

 hedges of the southern hills ; [Mexico to Venezuela]. 



