Yellow and Orange 



the juices are used as a water color, and to dye candies — in short, 

 this genus Opiiiitia and allied clans have great commercial value. 



The Western Prickly Pear (O. humifusa) — O. Rafinesquii of 

 Gray — a variable species ranging from iVlinnesota to Texas, is 

 similar to the preceding, but bears a larger flower, and longer, 

 more rounded, deeper green joints, beset with not numerous 

 spines, scattered chiefly near their margins. A few detlexed spines 

 in a cluster leave the surface where a tiny awl-shaped leaf and a 

 tuft of reddish brown hairs are likewise usually found. 



Evening-Primrose; Night Willow-herb 



{Onagra biennis) Evening-primrose family 

 (OEnothera biennis of Gray) 



F/owers — Yellow, fragrant, opening at evening, i to 2 in. across, 

 borne in terminal leafy-bracted spikes. Calyx tube slender, 

 . elongated, gradually enlarged at throat, the 4-pointed lobes 

 bent backward ; corolla of 4 spreadmg petals ; 8 stamens ; i 

 pistil ; the stigma 4-cleft. Stem : Erect, wand-like, or 

 branched, i to s ft. tall, rarely higher, leafy. Leaves : Al- 

 ternate, lance-shaped, mostly seated on stem, entire, or ob- 

 scurely toothed. 



Preferred Habitat — Roadsides, dry fields, thickets, fence-corners. 



Ftowcring Season — June — October. 



Distribution — Labrador to the Gulf of Mexico, west to the Rocky 

 Mountains. 



Like a ball-room beauty, the evening primrose has a jaded, 

 bedraggled appearance by day when we meet it by the dusty 

 roadside, its erect buds, fading flowers from last night's revelry, 

 wilted ones of previous dissipations, and hairy oblong capsules, 

 all crowded together among the willow-like leaves at the top of 

 the rank growing plant. But at sunset a bud begins to expand 

 its delicate petals slowly, timidly — not suddenly and with a pop, 

 as the evening primrose of the garden does. 



Now, its fragrance, that has been only faintly perceptible 

 during the day, becomes increasingly powerful. Why these 

 blandishments at such an hour ? Because at dusk, when sphinx 

 moths, large and small, begin to fly (p. 249), the primrose's 

 special benefactors are abroad. All these moths, whose length of 

 tongue has kept pace with the development of the tubes of certain 

 white and yellow flowers dependent on their ministrations, find 

 such glowing like miniature moons for their special benefit, when 

 blossoms of other hues have melted into the deepening darkness. 

 If such have fragrance, they prepare to shed it now. Nectar is 



21 321 



