VERVAIN FAMILY. 339 



4. DIANTHERA. (Greek for double anther, alluding to the two 

 separated cells on each filament.) Flowers all summer. 2Z 



D. humilis, Engelm. & Gray. Muddy banks of streams S. Car., S. ; 

 4'-8' high, smooth, with lance-ovate, short-petioled leaves longer than 

 the 3-4-flowered peduncles in their axils, and small pale purple flowers. 



D. Americana, Linn. Wet borders of streams ; 2 high, smooth, with 

 long linear-lanceolate leaves, and long peduncles (4'-6' long) bearing an 

 oblong spike of pale purple flowers. 



5. DICLIPTERA. (Greek words for double, wing, from the 2-valved 

 pod.) 



D. brach&ta, Spreng. Low banks, N. Car., S. ; is nearly smooth, 

 with 6-angled stem bearing many branches, thin ovate-oblong pointed 

 leaves on slender petiole and interrupted spike-like clusters of small 

 purple flowers, each with a pair of conspicuous flat bracts. If. 



LXXXVIII VERBENACEJJ, VERVAIN FAMILY. 



Plants with opposite (or sometimes whorled) leaves, differ- 

 ing from the other orders with irregular monopetalous and 

 didynamous or tetrandrous flowers by the ovary not 4-lobed 

 and with a single ovule in each of its (1-4) cells, the fruit 

 either fleshy or when dry at length splitting into as many 

 1-celled indehiscent nutlets. Plants seldom aromatic. 



* Ovary 1-celled and 1-ovuled. 



1. PHBYMA. Flowers in slender loose spikes. Calyx cylindrical, 2-lipped, the upper lip 



of 8 slender-pointed teeth, the lower short and 2-toothed. Corolla tubular, 2-lipped, 

 the upper lip notched, lower larger and 3-lobed. Stamens included. Ovary forming 

 a simple akene in the calyx. Herbs. 



* * Ovary 2- or more-celled, with few to several ovules. 

 4- Flowers in heads, spikes, or racemes, the flowers expanding from below upwards. 



2. LANTANA. Flowers in heads or short spikes. Calyx minute, obscurely 4-toothed. 



Corolla with an unequal 4-cleft spreading border, the upper lobe sometimes notched. 



Stamens included. Ovary 2-celled, becoming berry-like, and containing 2 little stones 



or nutlets. Shrubs or herbs. 

 8. LIPPIA. Flowers in heads, spikes, or racemes. Calyx tubular, 2-5-toothed. Corolla 



tubular, with 5-lobed 2-lipped border, the lower 8-lobed lip larger. Stamens included. 



Ovary and dry fruit 2-celled, 2-seeded. 

 4. VERBENA. Flowers in spikes or heads. Calyx tubular or prismatic, 5-ribbed and 



plaited. Corolla salver-form, the tube often curved, the border rather unequally 5- 



cleffc. Stamens included ; upper pair sometimes wanting the anthers. Ovary 4-celled, 



at maturity splitting into 4 dry akenes or nutlets. Herbs. 



+- +- Flowers cymose, expanding from above (or center') downwards. 



H- Flowers nearly regular, in cymes from the axils of the simple leaves ; shrubs. 



6. CALLICAEPA. Calyx 4-5-toothed, short. Corolla tubular-bell-shaped, short, 4-5- 



lobed. Stamens 4, protruded, nearly equal. Ovary 4-celled, in fruit berry-like, with 



4 little stones. ^ ^ F i owers irregular. 



6, VITEX. Calyx 5-toothed. Corolla tubular (tube short), with a spreading 2-lipped 

 border, the lower lip 3-parted and rather larger than the 2-lobed upper lip. Stamens 

 4> protruded, as is the style. Ovary 4-celled, becoming berry -like in the fruit, which 



