Yellow and Orange 



secreted in tubes so deep and slender that none but the moths' 

 long tongues can drain the last drop. An exquisite, little, rose-pink 

 twilignt flyer, his wings bordered with yellow, flutters in ecstasy 

 above the'evening primrose's freshly opened flowers, transferring 

 in his rapid flight some of their abundant, sticky pollen that 

 hangs like a necklace from the outstretched filaments. By day 

 one may occasionally find a little fellow asleep in a wilted blos- 

 som, which serves him as a tent, under whose flaps the brightest 

 bird eye rarely detects a dinner. After a single night's dissipa- 

 tion the corolla wilts, hangs a while, then drops from the matur- 

 ing capsule as if severed with a sharp knife. Few flowers, 

 sometimes only one opens on a spike on a given evening a plan 

 to increase the chances of cross-fertilization between distinct 

 plants; but there is a very long succession of bloom. If a flower 

 has not been pollenized during the night it remains open a while in 

 the morning. Bumblebees now hurry in, and an occasional hum- 

 ming bird takes a sip of nectar. Toward the end of summer, when 

 so much seed has been set that the flower can afford to be gener- 

 ous, it distinctly changes its habit and keeps open house all day. 

 During our winter walks we shall see close against the 

 ground the rosettes of year-old evening primrose plants ex- 

 quisitely symmetrical, complex stars from whose centre the 

 flower stalks of another summer will arise. (Illustration, p. 334.) 



Floriform sunshine bursts forth from roadsides, fields, and 

 prairies when the Common Sundrops (Kneiffia fructicosa) 

 formerly OEnothera fructicosa is in flower. It is first cousin 

 to the similar evening primrose of taller, ranker growth. Often 

 only one blossom on a stalk expands at a time, to increase the 

 chances of cross-fertilization between distinct plants ; but where 

 colonies grow it is a conspicuous acquaintance, for its large, bright 

 yellow corollas remain open all day. Bumblebees with their long 

 tongues, and some butterflies, drain the deeply hidden nectar; 

 smaller visitors get some only when it wells up high in the tube. 

 As the stigma surpasses the anthers, self-fertilization is impossible 

 unless an insect blunders by alighting elsewhere than on the 

 lower side, where the stigma is purposely turned to be rubbed 

 against his pollen-laden ventral surface when he settles on a 

 blossom. Unable to reach the nectar, mining and leaf-cutter bees, 

 wasps, flower flies, and beetles visit it for the abundant pollen; 

 and the common little white cabbage butterfly (Pieris protodice) 

 sucks here constantly. The capsules of the sundrops are some- 

 what club-shaped and four-winged, angled above, with four inter- 

 vening ribs between. Range from Nova Scotia to Georgia, west 

 beyond the Mississippi. (Illustration, p. 324.) 



A similar, but smaller, diurnal species (K. pumilla), likewise 

 found blooming in dry soil from June to August, has a more 

 westerly range North and South. 



322 



