1008 



VEKBENACEAE 



1. VERBENA L. 



Annual biennial or perennial herbs or shrubby plants. Leaves opposite : blades 

 entire, toothed, cleft or dissected. Flowers in spikes. Calyx sessile : tube often funnel- 

 form or salverform. Corolla white or of various colors : tube straight or curved : lobes 5, 

 nearly equal, or unequal and the limb 2-lipped. Stamens 4, didynamous or rarely 2, 

 included. Anthers with connectives sometimes furnished with a gland. Ovary 4-celled : 

 stigma 2-lobed, one lobe stigmatic. Ovules solitary in each cavity. Fruit an aggregate 

 of 4 nutlets enclosed in the calyx, without a stylopodium. VERBENA. 



Anthers not appendaged. 



Spikes very slender and much interrupted at maturity. 

 Leaf-blades 1-2 pinnately cleft or incised. 



Bract much shorter than the calyx at maturity. 



Fruit little longer than thick. 1. V. officinalis. 



Fruit about twice as long as thick. 



Bracts as long as the calyxes during anthesis. 2. V. riparia. 



Bracts % as long as the calyxes during anthesis. , 3.- V. Halei. 



Bract about as long as the calyx at maturity, or about equalling it. 4. V. xutha. 



Leaf-blades merely toothed. 



Leaf-blades petioled : bract less than % as long as the calyx : fruit little 



longer than thick. 

 Mature sepals little longer than the fruit, the tips not meeting over the 



top. 5. V. urticaefolia. 



Mature sepals much longer than the fruit, converging over the top 



and meeting. 6. V. polystachya. 



' Leaf-blades sessile : bract over % as long as the calyx : fruit about twice 



as long as thick. 7. V. Carolinensis. 



Spikes stout, continuous by the imbricated or contiguous fruits or, if interrupted 



below, bract as long as the calyx or surpassing it. 

 Corolla-limb 2-9 mm. broad. 

 Bract shorter than the calyx. 



Spikes sessile or nearly so : corolla-limb 8-9 mm. broad : pubescence 



dense, soft. 8. V. stricta. 



Spikes peduncled : corolla-limb 2.5-6 mm. broad : pubescence sparse, 



rigid or wanting. 

 Spikes elongated, 6-20 cm. long, many times longer than thick. 



Leaf-blades of a lanceolate type, petioled. 9. V. hastata. 



Leaf-blades of a linear type, sessile. 10. V. angustifolia. 



Spikes short and stout, '2-4 cm. long, commonly 4-5 times longer 



than thick. 



Leaf-blades sessile : spikes not crowded. 11. V. littoralis. 



Leaf-blades clasping : spikes crowded. 12. V. Bonariensis. 



Bract as long as the calyx or longer. 

 Stems upright. 



Spikes stout, 2-5 cm. long, dense : bract conspicuously surpassing 



the calyx : corolla-limb 6-7 mm. broad. 13. V.venosa. 



Spikes elongated, interrupted : bract as long as the calyx or a lit- 

 tle longer : corolla-limb about 4 mm. broad. 14. V. Neo-Mexicana. 

 Stems branched at the base, the branches prostrate or decumbent. 15. V. bracteosa. 

 Corolla-limb 10-13 mm. broad. 16. V. Tampensis. 

 Anthers of the longer stamens appendaged by a gland on the connective. 

 Calyx-lobes subulate : corolla 8-15 mm. long. 



Corolla-tube about % longer than the calyx, the limb 7-8 mm. wide. 17. V. ciliata. 



Corolla-tube slightly longer than the calyx, the limb 3-4 mm. wide. 18. V. pumila. 



Calyx-lobes setaceous-tipped : corolla 15-25 mm. long. 



Corolla-tube about % longer than the calyx, the limb 8-10 mm. wide. 



Bracts setaceous-attenuate, longer than the calyx at maturity : leaf-seg- 

 ments typically linear. 19. V. bipinnatifida. 

 Bracts narrowly lanceolate, shorter than the calyx at maturity : leaf-seg- 

 ments typically lanceolate. 20. V. ambrosifolia. 

 Corolla-tube about twice as long as the calyx, the limb 11-15 mm. wide. 



Leaf-blades pinnatifid or bipinnatifid. 21. V. Drummondii. 



Leaf-blades merely incised or incised-lobed. 



Leaf-blades typically of a lanceolate type, more or less cuneate at the 



base. 22. V. Lambertii. 



Leaf-blades typically of an ovate type, cordate or broadly truncate at 



the base. 23. V. Canadensis. 



1. Verbena officinalis L. Annual, slender. Stems 3-6 dm. tall, branching, nearly 

 glabrous : leaves 2-6 cm. long ; blades ovate to oblong or lanceolate in outline, 1-2-pin- 

 natifid, more or less incised : spikes very slender : calyx minutely puberulent to strigil- 

 lose, becoming about 2 mm. long : corolla blue or purple ; tube 3 mm. long ; limb 4 mm. 

 broad : nutlets oblong, barely 2 mm. long. 



In waste places and dry soil. Maine to Texas and Florida. Native of the Old World. Spring to fall. 



2. Verbena riparia Raf. Annual, stoutish. Stems 6-15 dm. tall, sparingly, pubes- 

 cent, widely branching : leaf-blades oblong to ovate, 4-12 cm. long, pinnatifid or nearly 

 3-parted below, prominently nerved beneath : spikes slender, interrupted : calyx minutely 



