MUSTAED FAMILY 37 



Priest's Eapids, Columbia Kiver, Douglas. Var. MiLLEFLORtrM Payson, Ann. Mo. Bot. Gard. 

 9:273 (1922). T. milleflorum Nels. Bot. Gaz. 52:263 (1911), type loc. New Plymouth, Ida., 

 Macbride 234. 



3. T. flavescens Wats. Stem 1 to 4 feet high, simple or with several much 

 elongated simple branches; herbage glaucous and glabrous, or somewhat hispid- 

 ulous; leaf -blades ovate to oblong-lanceolate, irregularly denticulate or toothed, or 

 sometimes with 2 to 4 pairs of broad salient lobes, sometimes markedly pinnatifid, 

 4 to 8 inches long, the lowest on petioles 1 to 2 inches long, the upper linear-lance- 

 olate, sharply serrate or denticulate, 1 to 4 inches long, sessile ; petals white, usually 

 much exceeding the sepals, the claw broad and the undulate limb narrow; pods 

 ascending, 1^4 "to 3 inches long, % line wide. 



Open valley floors or steep slopes of low hills, 50 to 2000 feet : Solano Co. to 

 eastern Contra Costa Co. and eastern Alameda Co., and south to San Benito Co. 

 Mar.-Apr. 



Tax. note. — This plant is another of the species which have fluctuated between Thelypodium 

 and Streptanthus. We have retained it in the former genus, though its flower is somewhat strep- 

 tanthoid. In Streptanthus it seems related to Streptanthus pilosus Jepson and S. hallii Jepson. 

 The stem is occasionally fistulous as in specimens from Antioeh. The stem hairs are short- 

 bristly and distinctly thickened downward. The cauline leaves are sessile, not auriculate as in 

 Streptanthus. The petals are dull white, perhaps never "yellow"; the limb is trough-shaped, its 

 margin undulate or sometimes not at all so. The anthers on dehiscence are sagittate, the fila- 

 ments all free. The ovary is commonly sparsely hirsute with spreading hairs (as in the type 

 specimen) or with only a few scattered hairs or sometimes quite glabrous. The pods are com- 

 monly glabrous. Mature fruit is seldom collected. The type was collected in California in 1831 

 by Douglas. The original description specifies "Monterey", but the type sheet (Herb. Hook., 

 Royal Botanic Gardens) carries no such indication. It is essentially improbable that the type 

 was collected at Monterey. The species has never been re-collected in that region, so far as we 

 know. Indeed, we have not thus far seen a Douglas (California) specimen which carries on the 

 herbarium sheet a definite station as recorded by Douglas. It has been thought by some that 

 Douglas visited Mt. Diablo. The circumstance of Thelypodium flavescens would give color to the 

 view that he penetrated as far east as the inner South Coast Eange. At Kew a tiny plant of 

 Streptanthus hispidus Gray, a species known only from the inner South Coast Eange, is mounted 

 with one of the T. flavescens collections made by Douglas. Of all our specimens the plants from 

 Willow Creek School, San Benito Eiver {Mason 5529), are nearest the Douglas type, especially 

 in leaf character and in the scarcely undulate petals. 



In the northerly parts of its range Thelypodium flavescens is relatively rare in iadiyiduals. 

 In the inner South Coast Eange, southward,' it occurs in dense well-defined colonies, chiefly on 

 steep hUlslopes where the light clay soil is highly friable. These colonies are 10 to 200 yards 

 across. One such very dense stand, the plants 2% to 314 feet high, inhabits the steep slope that 

 rises from the San Benito Eiver bottom on its east bank one and one-half miles northerly from 

 the Willow Creek School, where it is associated with Monolopia major DC. and Phacelia tanace- 

 tifolia Benth. On the east side of Little Rabbit Valley, San Benito Co., a large sharply defined 

 colony of five or sis acres was found in 1932. In the imier South Coast Eange south of San Benito 

 Co., Thelypodium flavescens seems to be replaced by Thelypodium lemmonii. 



Locs.— Main Prairie, Solano Co., Jepson 13,402; Benicia HHls, Sonne; Montezuma Hills, 

 Jepson 13,403; CoUinsville ; Antioeh, Davy 969; Clayton, Chesnut 4- Drew; Livermore (e.of), 

 Greene; Corral Hollow, May Arnold; Willow Creek School (11/2 miles n. of), on hillslope nsmg 

 from San Benito River bed, Jepson 16,126; Little Rabbit Valley, San Benito Co., Jepson 16,133. 



Refs.— Thelypodium flavescens Wats. Bot. King 25 (1871) ; Greene, Fl. Fr. 263 (1891) ; 

 Jepson, Man. 412 (1925). Streptanthus flavescens Hook. Ic. PI. t. 44 (1836), type from Cal., 

 Douglas, almost surely not "Monterey"; Torr. Pac. R. Rep. 4:65 (1854), Benicia, Bigelow. 

 T. greenei Jepson, Fl. W. Mid. Cal. 2i2 (1901), ed. 2, 181 (1911). T. flavescens Jepson, il.cc. 

 Streptanthus flavescens Gray, Proc. Am. Acad. 6:186 (1864). S. procerus Brew.; Gray, Proc. 

 Am. Acad. 6:519 (1865), type loc. coal-mine near Mt. Diablo, Brewer 1127 (the number as shown 

 in Gray Herb.). Caulanthus procerus Wats. Bot. King 27 (1871). T. procerum Greene, Fl. ±r. 

 263 (1891). T. hooTceri Greene, I.e. Caulanthus flavescens Payson, Ann. Mo. Bot. Gard. 9:^01 

 (1922). Guillenia flavescens Greene, Lflts. 1:228 (1906). G. hooTceri Greene, I.e. The above 

 citations illustrate the extent to which sjTionymy can accumulate about a species that is not really 

 very variable, but whose generic status is imcertain. 



4. T. lemmonii Greene. Stem simple or with few erect branches, 1 to 3 feet 

 high; herbage glabrous, glaucous; blades of lower leaves oblong, repand-dentate 



