1062 EHIXANTHACEAE 



3-flowered, glandular-pubescent : calyx-lobes lanceolate or oblong-lanceolate, 6-10 mm. 

 long, acute : corolla rose-purple, about 2.5 cm. long, the tube gradually dilated : stami- 

 nodium glabrous. 



On hillsides, central Texas. Spring. 



17. Pentstemon Helleri Small. Puberulent, or glabrate below the inflorescence, 

 thence minutely glandular-pubescent. Stems 3-6 dm. tall : leaves lustrous ; blades various, 

 those of the basal and lower stem-leaves oblong-spatulate or nearly linear, 6-10 cm. long, 

 acute, narrowed into winged petioles, those of the upper leaves oblong to broadly ovate, 

 acute, sessile, all undulate or slightly toothed : calyx-lobes densely glandular-pubescent, 

 ovate to elliptic-ovate, 8-10 mm. long, acutish : corolla white or rose, sometimes 

 tinged with blue, minutely glandular-pubescent, 3-3.5 cm. long, rather gradually en- 

 larged : capsules conic-ovoid, at least 1 cm. long, not reticulated, much surpassing the 

 calyx. 



On prairies, central Texas. Spring. 



18. Pentstemon Cobafea Nutt. Pubescent, at least above. Stems 3-6 dm. tall ; 

 leaves various ; those of the basal and lower stem-leaves with spatulate or oblong blades 

 narrowed into margined petioles ; upper stem-leaves few ; blades oblong to ovate, 4-12 cm. 

 long, partly clasping, nearly entire or sharply serrate : calyx-lobes ovate-lanceolate, 1-1.5 

 cm. long, rather acute : corolla 3.5-6 cm. long, dull reddish purple or paler, glabrous 

 within : staminodium sparingly bearded : capsules ovoid, about 1.5 cm. long, reticulated, 

 shorter than the calyx or barely surpassing it. 



On prairies, Kansas to Texas. Spring. 



19. Pentstemon grandiflorus Nutt. Glaucous. Stems 3-9 dm. tall, simple or 

 nearly so. Basal and lower stem-leaves with spatulate or oblong blades 5-10 cm. long, 

 petioled : upper stem-leaves orbicular or ovate, 3-9 cm. long : panicle narrow: calyx-lobes 

 glabrous, lanceolate to oblong-lanceolate, 7-9 mm. long : corolla lilac or lavender-blue, 

 4.5-5 cm. long ; tube abruptly dilated below the middle : staminodium sparingly pubes- 

 cent near the apex : capsules ovoid, 2-2.5 cm. long, reticulated at maturity. 



On plains, Minnesota to South Dakota, south to Illinois, Indian Territory and Kansas. Summer. 



20. Pentstemon Murray^nus Hook. Glaucous. Stems 3-10 dm. tall : basal and 

 lower stem-leaves with spatulate or oblong blades 7-10 cm. long, narrowed into petiole-like 

 bases ; upper stem-leaves leathery ; blades connate-perfoliate, ovate to broadly oblong, 4-8 

 cm. long, often abruptly pointed : panicle narrow : calyx-lobes ovate, 4-5 mm. long, or 

 slightly larger at maturity, acute: corolla deep scarlet, 2.5-3 cm. long; tube gradually 

 dilated : staminodium glabrous : capsules ovoid, 1.5 cm. long, about § longer than the calyx. 



On prairies, Texas. Summer. 



11. PAULOWNIA Sieb. & Zucc. 



Trees simulating Catalpa, with flaky bark. Leaves opposite : blades ample, broadest 

 below the middle, entire or 3-lol)ed, long-petioled. Flowers in large terminal panicles. 

 Calyx-lobes 5. Corolla violet or pink-purple, 2-lipped : tube trumpet-shaped, the lobes of 

 both lips spreading. Stamens 4, included : anther-sacs divergent. Styles mostly united, 

 the tips stigmatic on the inner side. Capsule ovoid, leathery, loculicidally dehiscent. 

 Seeds numerous, Avinged. 



1. Paulownia tomentosa (Thunb. ) Baill. A tree with large spreading branches. 



Leaf-blades ovate or suborbicular, 1.5-4 dm. long, acute or acuminate, densely tomentose 



beneath, cordate, prominently nerved beneath : calyx 10-14 mm. long, densely tomentose ; 



lobes ovate to oblong : corolla violet, pubescent without, 4-5 cm. long, the limb 3.5-4.5 



cm. broad, the lobes rounded : capsules ovoid, 3-4 cm. long, acute. 



In waste places and thickets, New York to Florida and Texas. Naturalized from eastern Asia. 

 Spring and summer. 



12. MIMULUS L. 



Annual or perennial caulescent herbs. Leaves opposite : blades flat, toothed. 

 Flowers solitary in the axils, sometimes disposed in racemes or panicles. Calyx-tube 

 angled, longer than the lobes. Corolla of various colors, 2-lipped : tube with 2 ridges 

 within on the lower side : upper lip spreading or reflexed : lower lip erect. Stamens 4 : 

 filaments partly adnate to the corolla-tube : anther-sacs divergent. Styles united to the 

 2-lobed stigma. Capsule loculicidally dehiscent, enclosed in the calyx. Monkey-flower. 



