CAPER FAMILY 15 



contracted upon its seed and falling away with it, therefore like a nutlet. — Species 

 2, North America. (Dr. A. Wislizenius, who collected in early days in California.) 



1. W. refracta Engelm. Jackass Clover. Branching, 1 to 2 (or 6) feet high; 

 leaflets obovate to oblong, 4 to 9 lines long, rather longer than the petiole; raceme 

 dense, in age usually much elongated; petals II/2 lines long; stamens and ovary 

 exserted; pods 1^ to 2 lines broad, the lobes strongly divergent and crested or 

 toothed at apex, the cells separated by a partition with a single rather large per- 

 foration; stipe in fruit 2 to 4 lines long; style persistent and bristle-like; nutlets 

 obovoid, usually reticulate and ridged and with coroniform tubercles or horns at 

 summit, sometimes smooth. 



Alkaline plains, 100 to 2300 feet : Sacramento to Lathrop and southward in the 

 San Joaquin Valley as an immigrant; Colorado Desert. East to New Mexico and 

 Texas. Apr.-Nov. 



Variability of fruit. — A number of forms have been segregated as species from the original 

 W. refracta Engelm., chiefly on the basis of differences in the shape and more especially differ- 

 ences in the tubercles on the fruit. The fruits are variable. In plants of the Great Valley the 

 nutlets are somewhat ridged, somewhat reticulate and provided with a coronal crest of tubercles 

 or warts. Sometimes again the warts are developed into horns. The tubercles or horns often differ 

 in degree of development, on different plants, or the two nutlets on one fruit may sometimes be 

 unlike. The fruits of the Great Valley plants do not differ essentially from those of the western 

 Colorado Desert or of western Texas. On the other hand plants from the southern Mohave 

 Desert at Twenty-nine Palms have the fruits almost smooth. The capsules are, however, unstable 

 in these characters, and the plants on the whole so uniform and constant in every other, that we 

 are disposed to look upon these peculiarities of the fruit as not useful for specific characters. 

 Obovate and pyrif orm valves, for example, may occur on the same plant. Reticulations on obovate 

 valves may be as distinct as in the case of the pyriform valves. The patterns of the ridges and 

 reticulations, of the warts and horns, are of such a nature as to lead one to believe that the varia- 

 tions in the fruit represent sometimes differences in degree of development, sometimes fluctuating 

 variability. 



History of the species in the Great Valley. — In the San Joaquin Valley Wislizenia refracta 

 is an introduction and was probably introduced during the early decades of the American occu- 

 pation, since it had been noted as occurring there for a long period. A. L. Wiuchell, a local his- 

 torical authority at Fresno, remembers the plant as growing in Fresno Co. on the west side of the 

 San Joaquin River previous to 1870. Others recall the plant in that district for thirty years past. 

 H. W. Shafer, an engineer of Selma, first observed the plant on Poso Creek east of Formosa in 

 1886, and also near Traver; he believes it to be an immigrant. From Goshen it was sent to us 

 in 1900. In 1928 we noted it along the railway lines in Tulare Co. and observed its behavior on 

 the alkali plains west of Fresno where it is very common. As observed north of Kerman, the 

 plant seemed as if it had the habit of appearing initially along the roadways, thence spreading 

 into the fields, especially moist ones broken by the plow. On the Fresno-Mendota road it con- 

 tinued to be more or less conspicuous on the plain as far west as the road station called Lone 

 Willows. It is our view that this species is undoubtedly an introduction into the Great Valley 

 from the southwards. In 1901 it was thought to be more common in. the lower San Joaquin Valley 

 than it had been formerly (cf. Fl. "W. Mid. Cal. 230). It was not collected by Brewer, Bolander 

 or any of the other early day collectors in the San Joaquin Valley. So conspicuous a plant could 

 not well have been missed. 



On account of the attraction that the flowers possess for insects, the plant has been noted 

 by bee-keepers for many years. Under date of Nov. 18, 1900, O. L. Abbott writes from Selma: 

 "In this district it is never called by any name other than Stinkweed. It grows best about six 

 miles north of Goshen on ground white with alkali. Bumblebees, yellow butterflies and a very 

 small bee are strongly attracted by its flowers, which indicates that it is a profuse yielder of 

 nectar. I have never seen the honey bee on its blossoms." Contrariwise, other bee men (espe- 

 cially in recent years) regard this species as a valuable plant to the honey bee industry. 



Locs. — Elk Grove, Drew; Lathrop, Bioletti; Fresno, I. T. Walker; Goshen, 0. L. Ahiott; 

 Visalia, Congdon; Traver, Jepson 13,312; Twenty-nine Palms, s. Mohave Desert, Jepson 12,632; 

 Borrego Valley, J. T. Hoivell 3237. 



Refs.— Wislizenia eefracta Engelm.; Wisliz. Tour n. Mex. 99 (1848), type loc. El Paso, 

 Tex., WisUsenius; Gray, PI. Wright. 1:11, t. 2 (1852) ; Jepson, Fl. W, Mid. Cal. 230 (1901), ed. 

 2, 194 (1911), Man. 409, fig. 405 (1925). W. calif ornica Greene, Proc. Biol. Soc. Wash. 19:130 

 (1906), type by Greene from the Great Valley (probably Lathrop, where he once collected it). 

 W. divaricata Greene, Proc. Biol. Soc. Wash. 19:130 (1906), type loc. Borrego Sprs. (not 

 "Bonego"), Colorado Desert, Orcutt. 



