PEA FAMILY 247 



Variation. — The representation of the genus Lupinus in California is large and variable. 

 The natural units cannot readily be segregated because reliance can seldom be had on single or 

 few characters. On the other hand individual plants, on the whole, fall somewhat readily into 

 natural groups on the basis of the sum total of their characters. An intensive study of such 

 natural groups reveals the features that are variables in greater degree, or variables in less 

 degree, so that one gives proportionate weight to the various characters. By this method the 

 confusion often evident in determining the systematic relationships of Lupines will to some 

 extent be avoided, although in a few cases of complex groups it has been necessary to define the 

 prevailing condition, the mean about which the whole group fluctuates, because it is not possible 

 to establish sharply defined boundaries. 



Habit is a fairly useful feature, although in certain cases it may be extremely variable. 

 Lupinus albifrons Benth. departs from its usual shrub form (5 to 12 feet high) and becomes 

 low and suffrutescent (var. coUinus Greene) or even practically herbaceous (var. austromontanus 

 Jepson). The open or congested habit of the foliage, the relative length of stems, peduncles 

 and racemes are so dependent upon the conditions under which growth takes place that in most 

 groups they are uncertain for use in segregation, even for the segregation of varieties. In the 

 Lupinus lepidus group such characters and also size of flowers and denseness or laxity of racemes 

 have been generally used by authors for segregation. The plants, however, vary widely in these 

 respects and show almost every possible combination of variations within the group. A similar 

 range of variables is shown by Lupinus coneinnus Agardh and L. sparsiflorus Benth. A com- 

 plete recognition of such variations as species or even as varieties would extend the systematic 

 account far beyond the point of usefulness. In such a complex the prevailing form is given 

 specific standing, the more definite or striking local races recognized as varieties. 



In some groups the plants are to all appearances so readily stimulated by the environmental 

 factors in a territory apparently recently occupied, that the characters which serve to define the 

 species in its typical phase, fail altogether to characterize the less stable phases. The group 

 Lupinus albicaulis in its extreme form, L. formosus Greene, reaches a stable phase on the floor 

 of the Great Valley as to robust habit, density of pubescence, length of racemes and the size 

 and shape of the banner, wings and keel of the flower; but on the margins of the range of L. 

 formosus in the foothills the representatives of the group are highly variable. Thus in the case 

 of certain of these variants every character utilized to set apart typical L. formosus from typical 

 L. albicaulis has been lost. Satisfactory key characters in such groups are obviously not to be had. 



Technical floral characters have been depended upon hitherto more than is justifiable. 

 Ciliation of the keel is useful in certain cases, but implicit reliance upon it leads to confusion. 

 Lupinus albifrons Benth. and L. bicolor Lindl. both have a characteristically ciliate keel, but 

 variants occur in each in which the keel is non-ciliate. Lupinus coneinnus Agardh has a non- 

 ciliate keel, but has also local races with the keel ciliate as in L. sparsiflorus Benth. In Lupinus 

 microcarpus Sims the keel may be ciliate on both margins, on either or neither. The shape of 

 the banner is similarly variable and neither the banner nor keel ciliation serve for the segrega- 

 tion of species or even varieties. Calyx characters are often in like case. In Lupinus micro- 

 carpus the lower lip of the calyx may vary from broadly oblong to narrowly lanceolate, from 

 entire through all gradations to deeply bifid or trifid, and the upper lip from entire to bifid. 

 "When this character is utilized for varietal segregation it results in artificial groupings. Even 

 local races and plants of one form in a small area, as in the Eichmond district, may vary widely 

 in this respect. The calyx character is similarly unreliable in L. bicolor Lindl. and L. micranthus 

 Dougl. 



The seeds of many lupines are beautifully and strikingly patterned; they also differ widely 

 in size and shape and it is possible that a more complete knowledge of them would be of value 

 in determining relationships. 



Field note. — Some lupine species are undoubtedly poisonous to cattle, horses or sheep, 

 but experimental investigation of Californian species thus far is not in every case conclusive. 

 Perhaps only a few species are involved and probably it is, in most cases, the seeds which 

 produce unfavorable symptoms. The herbage of the annual lupines, such as Lupinus bicolor, 

 often forms a considerable or even major portion of cut hay in certain portions of the Great 

 Valley and is freely used in all stages of growth for fodder. We have noticed that riding 

 animals of one's botanical pack train when on the trail eagerly eat tufts of the herbage of 

 Lupinus albifrons. Sheep men in the Sierra Nevada on the watershed of the San Joaquin 

 Eiver value the mature or naturally dried herbage of Lupinus albicaulis for their flocks. On 

 the other hand we have often observed the general herbage of meadows, caiion flats or cupped 

 hollows in the Sierra Nevada cropped close to the ground, but spotted by dense colonies of 

 Lupinus rivularis left untouched by horned cattle, or on the whole little disturbed, either in 

 flower or in fruit. The seeds of Lupinus microcarpus are sometimes harvested on the upper 

 San Benito Eiver benches and fed to barnyard fowl, the settlers believing that egg production 

 is thereby stimulated. The mourning dove feeds extensively upon the seeds of Lupinus bi- 

 color and doubtless other annual species. In the Great Valley Lupinus formosus is sometimes 

 troublesome as a weed in rich fields. So far as observed all our shrubby species are evergreen. 

 Of these shrubby species one, Lupinus arboreus, is especially valuable as a covering on shift- 



