PEA FAMILY 251 



Pods hairy; calyx hairy or villous, its lips very unequal; racemes shorter than or equaling the 

 leaves. 

 Pods constricted between the seeds, densely hirsute; racemes 1 to 2y2 inches long; seeds flat, 



rugulose 48. L. pusillus. 



Pods not constricted between the seeds; racemes at first subcapitate; seeds lenticular, 

 polished 49. L. hrevicaulis. 



Section 1. — Perennials. 



1. L. albifrons Benth. Silver Lupine. Rounded very leafy shrub II/2 to 5 

 (or 12) feet bigli, usually with a distinct woody trunk; herbage silky-pubescent, 

 the leaves silvery-silky; leaflets 7 to 10, oblanceolate, % to 1 (or 1^4 ) inches long; 

 petioles % to 1% inches long; racemes loose or at least not dense, 3 to 12 inches 

 long, the whorls definite or indefinite; flowers 5 to 7i/4 lines long; pedicels II/2 to 

 4 lines long ; upper calyx-lip broad, cleft, the lower entire or toothed ; petals blue, 

 subequal ; banner broad, the whitish or yellow spot early changing to red-purple, 

 a little pubescent on middle of back near apex ; keel minutely or sparingly ciliate ; 

 pods villous, 1 to 1% inches long, 5 to 9-seeded. 



Sandy or dry loam, hillsides and carions, 50 to 4000 (or 6700) feet: Coast 

 Ranges from Humboldt Co. to Santa Barbara Co. Sierra Nevada from Shasta 

 Co. to Tulare Co.; coastal Southern California. Mar.-July. 



Geog. note. — One of the most abundant and widespread of our perennial Lupines, Lupinus 

 albifrons is often gregarious on hillslopes and dominant over considerable areas. Crowded with 

 long erect racemes, it is, with its silvery foliage, usually a striking object in the landscape of the 

 hill country of the seaward Coast Eanges. Sometimes a canon is all silver with a pure stand of 

 the species. It is less common in the Sierra Nevada foothills, whence the seeds, however, are 

 often carried down by freshets to the floor of the east side of the San Joaquin Valley, where con- 

 siderable colonies occasionally grow on the river benches or flood beds of the Chowchilla Eiver, 

 Fresno Eiver and other winter streams. Bushes in this region become 4 to 12 feet high, thus 

 attaining the greatest size of any species in the genus so far as known to us. These remarkable 

 plants of the valley floor were first observed in 1844 by Captain John C. Fremont who, on the 

 east side of the San Joaquin Valley between the Calaveras and Stanislaus rivers, made note of 

 them in his journal as follows : "About 1 o'clock we came again among innumerable flowers ; and 

 a few miles further, fields of the beautiful blue-flowering lupine, which seems to love the neighbor- 

 hood of water, indicated that we were approaching a stream. We here found this beautiful shrub 

 in thickets, some of them being 12 feet in height. Occasionally three or four plants were 

 clustered together, forming a grand bouquet, about 90 feet in circumference, and 10 feet high; 

 the whole summit covered with spikes of flowers, the perfume of which is very sweet and grateful. 

 A lover of natural beauty can imagine with what pleasure we rode among these flowering groves, 

 which filled the air with a light and delicate fragrance" (Eep. Expl. Exped. to Ore. and Cal. 249). 



In coastal Southern California Lupinus albifrons is relatively rare but has developed a 

 number of variants of special ecological interest in connection with their semi-arid or desert 

 habitats. These are described below. 



Note on variation. — Throughout its range Lupinus albifrons is recognizable as a well defined 

 natural unit. Its abundant silvery leaves are quite constant in shape and size, and the sterile 

 branchlets with small crowded leaves are often a characteristic feature. Minor variations have 

 been made the basis of several specific segregates, which apparently have little significance 

 either structurally or geographically. The plants in less favorable habitats are sometimes with- 

 out distinct trunks, the branches more or less decumbent from a woody caudex (L. collinus Hel.). 

 The pubescence of pedicels, spreading in the original plants, is sometimes appressed (L. brittonii 

 Abrams, L. eminens Greene). Our material indicates that this condition is constant in the most 

 northerly portion of the state and that it is more common at higher altitudes, but it occurs else- 

 where, and there are many intermediates with pubescence sub-appressed or ascending. In certain 

 plants from Marin and Monterey counties the floral bracts are long and conspicuous in the bud 

 (i. douglasii Agardh). Large-flowered phases are common; color variations apparently less so. 

 Albino and pink-flowered plants are sometimes observed in the field. The banner spot varies from 

 white to yellow, changing after fertilization to violet or tawny red. The non-ciliate keel is 

 occasional, but has not proved constant in any of the forms in which it has been utilized as a 

 segregating character. In L. albifrons and the varieties douglasii and collinus the keel is nar- 

 row (1% to 2 lines wide), while in the varieties haUii, austromontanus and johnstonii it is 

 broad (2^/^ to 3 lines wide). This distinction, though not invariable, is extremely constant. The 

 specimens next cited are regarded as essentially representative of the species. 



Locs. — Coast Eanges: Yreka, Butler 1268; Crane Creek, e. Tehama Co., Jepson; Weitchpek, 

 n. Humboldt Co., Chandler 14:24: ; Lasseeks Peak, Humboldt Co., Goddard 659; Burr Creek, 

 Humboldt Co., Tracy 4707; Mt. St. Helena, Jepson; Calistoga, Jepson 53t; Oakley, Contra 



