VERBENACEAE 1011 



20. Verbena ambroslfolia Rydb. Resembling V. bipinnatifida but larger. Stems 

 and foliage less hirsute : leaf-blades less deeply and less finely divided, the segments typi- 

 cally lanceolate : calyx becoming 8-9 mm. long ; lobes setaceous-tipped, surpassing the 

 bracts : corolla limb 6-8 mm. wide : nutlets 2.5 mm. long, coarsely wrinkled all over. 



In dry or stony soil, South Dakota and Colorado to Texas, Arizona and Mexico. Spring and 

 summer. 



21. Verbena Drummdndii (Lindl. ) Baxt. Perennial, but often flowering early. 



Stems often branched at the base, the branches 2-4 dm. long, hirsute : leaf-blades 2-5 cm. 



long, pinnatifid or bipinnatifid, the segments typically narrow : calyx becoming 9-10 mm. 



long, surpassing the bract at maturity : corolla limb fully 11 nun. wide : nutlets over 3 mm. 



long, wrinkled from below tlie middle to the apex. 



On prairies, or in sandy bottoms or woods, Virginia to Kansas, Texas and New Mexico. Spring 

 and summer. 



22. Verbena Lambertii Sims. Perennial. Stem commonly branched at the base, 

 the branches hirsute : leaf-blades 3-9 cm. long, typically of a lanceolate type, incised or in- 

 cised-lobed, acute or acuminate at the apex, more or less cuneately narrowed at the base : 

 calyx becoming 11-13 mm. long, surpassing the bract : corolla-limb 11-13 mm. wide : nut- 

 lets about 3 mm. long, shallowly wrinkled throughout. 



In sandy or dry soil, Tennessee to Arkansas, South Carolina, Florida and Texas. Spring and 

 summer. 



23. Verbena Canadensis (L. ) Britton. Perennial, stouter than the two preceding 

 species. Stem or branches 3-6 dm. long, minutely pubescent or puberulent : leaf-blades 

 3-8 cm. long, typically of an ovate type, incised or incised-Iobed, rather rounded at the 

 apex, cordate or broadly truncate at the base : calyx becoming 12-14 mm. long, mainly 

 surpassing the bract : corolla-limb 12-15 mm. wide : nutlets 3.5 mm. long, wrinkled all over. 



On prairies, Illinois to Florida and Texas. Spring to fall. 



2. HELLERANTHUS Small. 



Annual pubescent herbs, more or less diffusely branched from the base. Leaves oppo- 

 site : blades pinnatifid or parted. Flowers in terminal compact spikes, each subtended by 

 a narrow bract. Calyx tubular, 5-lobed. Corolla white or pink : tube terete : limb 5- 

 lobed. Stamens 4, didynamous : anthers unappendaged. Ovary 4-celled, surmounted by 

 a hemispheric stylopodium. Stigma 2-lobed, one lobe stigmatic. Ovules solitary in each 

 cavity. Fruit an aggregate of 4 tardily separating nutlets, the group surmounted by a 

 pyramidal stylopodium, the whole enclosed in the calyx. 



1. Helleranthus quadrangnlatus (Heller) Small. Foliage hirsute. Stems branched 

 at the base ; branches spreading or prostrate, 1-3 dm. long, forking : leaves numerous ; 

 blades 1-2.5 cm. long, broadly ovate, incised-pinnatifid, or some 3-parted, the lobes incised 

 or cleft, surfaces strigose-hirsute : spikes dense, 1-3 cm. long : bracts narrowly lanceolate, 

 shorter than the calyx : calyx bristly, becoming 5 mm. long ; lobes acute : corolla white 

 to pink; tube surpassing the calyx ; limb 2.5-3 mm. broad, the lobes notched : fruit in- 

 cluded, constricted at the middle, surmounted by a pyramidal stylopodium whose angles 

 alternate with lobes. [ Verbena quadrangulata Heller.] 



In dry soil, Texas. Summer. 



3. PHYLA Lour. 

 Perennial caulescent procumbent or creeping herbs. Leaves opposite : blades flat, 

 toothed or lobed. Flowers perfect, in congested peduncled axillary spikes, each subtended 

 by a conspicuous persistent bract. Calyx membranous : tube flattened and 2-keeled, the 2 

 lateral lobes conduplicate. Corolla 2-lipped : tube incurved, terete : limb oblique, the 

 segments 4, often refuse or eroded. Stamens 4, didynamous, included : filaments short : 

 anthers with unappendaged connectives. Ovaiy 2-celled. Stigma oblique or recurved. 

 Ovules solitary in each cavity. Fruit dry, with a crustaceous or corky coat, tardily sepa- 

 rating into 2 nutlets. The plants flower from spring to fall. 



Leaf-blades with 1-4 pairs of salient remote teeth near the apex. 



Peduncles shorter than the subtending bracts or but little longer : fruit oval. 1. P. cuiieifolia. 



Peduncles much longer than the subtending bracts : fruit obovoid. 2. P. incita. 



Leaf-blades with several pairs of low approximate teeth. 



Leaf-blades mostly broadest above the middle, toothed from above the middle to 



the apex : calyx-lobes shorter than the tube : fruit pubescent at the apex. 3. P. nodiflwa. 



Leaf-blades mostly broadest below the middle, toothed from below the middle to 



the apex : calyx-lobes longer than the tube : fruit glabrous. 4. P. lanceolata. 



1. Phyla cuneifolia (Torr.) Greene. Foliage strigillose-canescent. Stems branched 

 at the base ; branches j^rocumbent, rarely, if ever, creeping, 2-10 dm. long, often branch- 



