Genus n. 



EVENING-PRIMROSE FAMILY 



1. Hartmannia speciosa (Xutt.) Small. 

 Showy Primrose. Fig. 3057.- 



Oe. sfeciosa Nutt. Journ. Acad. Phil. 2: 119. 1821. 

 Hartmannia speciosa Small, Bull. Torr. Club 23: 181. 

 1896. 



Erect, perennial, ascending or decumbent, more 

 or less branched, 6-3 high, puberulent or finely 

 pubescent. Stem-leaves lanceolate or linear- 

 lanceolate, sessile, or short-petioled, acutisli, sinu- 

 ate or pinnatifid, 2-3' long; basal leaves slender- 

 petioled, oval or oval-lanceolate, repand or pin- 

 natifid at the base; flowers white or pink, ii'-3*' 

 broad, generally few, loosely spicate; petals 

 broadly obovate, eniarginate ; calyx-lobes ovate- 

 lanceolate, acuminate, spreading, the tube rather 

 longer than the ovary; capsule club-shaped, 

 strongly 4-ribbed, 4-winged, pubescent, 6"-g" 

 long, on a short stout pedicel. 



Prairies, Missouri and Kansas to Louisiana, Texas, 

 Arizona and Mexico. May-July. Extensively natu- 

 -alized in Illinois, South Carolina and Georgia. 



12. PACHYLOPHUS Spach, Hist. \'eg. 4: 365. 1835. 



Perennial acaulesecnt or nearly acaukscent herbs. Leaves basal, leathery, pinnatifid or 

 pinnately-toothed, petioled. Flowers basal, more or less tufted. Calyx pubescent, its tube 

 linear-funnelform, its segments narrow, 2-3 times shorter than the tube. Petals white or 

 pink, spreading. Stamens 8; filaments filiform, the alternate ones longer; anthers linear. 

 United styles filiform; stigma 4-cleft. Capsules basal, woody, pyramidal, their angles retuse 

 or obtuse, transversely wrinkled. Seeds sessile, in i or 2 rows, deeply furrowed along the 

 raphe. [Greek, referring to the tuberculate edges of the valves of the capsule.] 



Five or six species, of western North America, the following typical. 



I. Pachylophus caespitosa (Xutt.") Rai- 

 mann. Scapose Primrose. Fig. 3058. 



Oenothera caespitosa Nutt. Fras. Cat. 18 13. 

 Oenothera scapigera Pursh, Fl. Am. Sept. 263. 1814. 

 P. Nuttallii Spach, Hist. Veg. 4; 365. 1835. 

 PacJiylophiis caespitosa Raimann in Engl. & Prantl, 

 Nat. Pfl. Fam. 3: Abt. 7, 215. 1893. 



Acaulescent or nearly so, perennial or biennial 

 from a thick woody root. Leaves clustered at the 

 base, narrowed into a slender petiole, lanceolate, 

 oblanceolate or oval, acutish at the apex, densely 

 pubescent, sinuate-dentate, often densely ciliate 

 with white hairs, repand or pinnatifid, 3'-8' long, 

 usually less than i' wide; flowers few, white or 

 rose, ii'-3' broad; petals obcordate ; lobes of the 

 calyx pubescent, narrowly lanceolate, reflexed- 

 spreading, its tube 2'-"' long, dilated at the mouth, 

 many times longer than the ovary; capsule sessile, 

 ovoid, strongly tuberculate on each side, the angles 

 ribbed ; seeds densely and minutely tuberculate. 



Plains, South Dakota to Nebraska, Colorado and 

 Utah. June-July. 



13. LA VAUXIA Spach, Hist. Veg. 4: 366. 1835. 



Low usually acaulescent herbs, rarely producing short stems. Leaves mostly basal, 

 pinnatifid, numerous. Flowers perfect, white, pink or pale yellow, Calyx-tube slender, 

 dilated at the throat; calyx-segments finally reflexed, the tips free in the bud or united. 

 Petals 4, spreading. Stamens 8, the alternate ones longer; filaments filiform; anthers linear. 

 Ovary short, 4-angled ; stigma 4-cleft; ovules few. Capsules stout, their angles- sometimes 

 winged above. Seeds few. [In honor of Francois Delavaux, founder of the botanical garden 

 at Nismes.] 



About 6 species, chiefly in southern North America. Type species : Lavaitxia triloba (Nutt.) 

 Spach. 



Leaves membranous ; capsules beaked, glabrate. i. L. triloba. 



Leaves leathery ; capsules hardly beaked, pubescent. 2. L. bracliycarpa. 



