286 ACANTHACK^I. 



P. leptostachya Linn. : leaves ovate, acute, coarsely and unequally toothed, 

 petioled ; spikes terminal, slender. 



Shady woods. Can. to Car. July. ^. Stem 23 feet high, with a few 

 spreading branches above. Leaves large. Spikes on long slender peduncles. 

 Flowers small, mostly opposite, purplish. Calyx reflected downwards when in 

 fruit. Lopseed. 



ORDER XCV. ACANTHACE^E. ACANTHADS. 



Calyx 4 or 5 -divided, usually 5 -leaved, distinct or variously 

 combined, persistent. Corolla mostly irregular, with the limb 

 ringent or bilabiate, or occasionally 1 -lipped, sometimes nearly 

 equal, deciduous. Stamens mostly 2, both bearing anthers ; 

 sometimes 4, didynamous, the shorter ones being sometimes 

 sterile. Ovary seated in the disk, 2-celled ; style 1 ; stigma 

 2-lobed or entire. Capsule 2-celled, bursting elastically with 

 2 valves. Seeds roundish, hanging by processes of the pla- 

 centa, without albumen. Herbaceous plants or shrubs. Leaves 

 opposite, without stipules. 



1. JUSTICIA. Linn. Justicia. 



(In honor of James Justice, a Scotch horticulturalist.) 

 Calyx 5-parted, often with 2 bracts at the base. Corolla 

 irregular, bilabiate ; upper lip emarginate ; lower 3-cleft. Sta- 

 mens 2, each with a single or double anther. Stigma 1. Cap- 

 sule attenuated, 2-celled, 2-valved ; dissepiment growing from 

 the centre of each valve. 



J. pedunculosa Mich. : leaves linear-lanceolate ; spikes axillary ; pedun- 

 cles elongated, mostly alternate; flowers crowded. J. Americana Void. 

 Dianthera Americana Linn. 



In water. Can. to Car. W. to Miss. July, Aug. 'ZJ.. Root creeping. 

 Stem 2 feet high, simple or sparingly branched above. Leaves nearly 6 inches 

 long, narrow-lanceolate. Flowers on axillary peduncles which are nearly as 

 long as the leaves, pale-purple. Water Willow. 



2. RUELLIA. Linn. Ruellia. 



(In honor of John Ruelle, a French physician and botanist.) 



Calyx 5-parted, often bi-bracteate. Corolla subcampanulate, 

 border 5-lobed. Stamens approximating by pairs. Capsule 

 attenuated at either extremity, bursting with elastic teeth. 

 Seeds few. 



R. strepens Linn. : erect, hairy ; leaves on petioles, opposite, lanceolate- 

 ovate, entire ; peduncles 1 3-flowered ; segments of the calyx linear-lan- 

 ceolate, very acute, hispid, shorter than the tube of the corolla. 



Shady woods. Penn. to Flor. W. to Miss. July. 11. Stem 812 inches 

 high. Flowers axillary, blue. Wkorled RueUia. 



