148 



POIiEMONIACEAE 



Locs. — Northern Sierra Nevada: Donner Lake, Sonne 233; Truekee, Sonne; Sierra Valley, 

 Jepson 8053; Eagle Lake, Lassen Co., Baher 4- Nutting ; Tamarack road at Johnson ranch, ne. 

 Shasta Co., M. S. Baler; upper Fall River Valley, ne. Shasta Co., Jepson 5752. North Coast 

 Eanges: Sherwood Valley, Mendocino Co., Davy 5162; Miranda, South Fork Eel River, Jepson 

 12,366; Trinity Summit, Manning 99. 



Refs. — Navaeretia minima Nutt., Jour. Acad. Phila. n. s. 1 :160 (1848), type loc. "plains of 

 the Oregon [Columbia River] near Walla-Walla," Nuttall; Jepson, Man. 791 (1925). Gilia mi- 

 nima Gray, Proc. Am. Acad. 8:269 (1870). 



a 





3. N. prostrata Greene. Plants prostrate ; primary flower-cluster or head ses- 

 sile at the ground, the branches radiating from beneath it 1 to 3 inches long, simple 



or rarely once forked, terminating in dense 

 heads; herbage glabrous; leaves pinnatifid, % 

 to 2 inches long, the rachis broad and elongated, 

 the segments remote; outer bracts foliaceous, 

 conspicuous (% to 1% inches long) , 2 to 5 times 

 as long as the heads ; inner bracts mostly trifid 

 at apex, chartaceo\is below, not exceeding the 

 corolla; calyx pubescent outside (sometimes 

 only scantily pubemlent) , a ring of hairs at the 

 base of the calyx-lobes inside, tlie lobes unequal, 

 the 2 longer tridentate; corolla white or pale 

 lavender, 31/2 lines long; calyx- teeth in fruit 

 contracted over the capsule ; capsule 2-celled, 

 9 to 11-seeded, the seeds small, agglutinated in 

 a mass as in N. intertexta and N. leucocephala. 

 Mesa.s and valleys, 50 to 1500 feet : Monterey 

 Co.; cismontane Southern California. May. 



Biol. note. — When individuals of certain native an- 

 nual species precociously develop a single flovrer or a 

 single flovcer-eluster as a sessile or subsessile inflores- 

 cence seated in a leaf rosette on the ground, such a 

 phenomenon is usually regarded as an adaptation to 

 arid or semiarid habitats of precarious or intermittent 

 rainfall. If continued moisture fail, such a develop- 

 ment represents the entire effort of the plant ; by this 

 adventure the flower or flower-cluster matures some 

 seed. On the other hand if there be renewed or con- 

 tinued precipitation under favorable conditions for 

 growth, the plant will produce a wheel of proliferating 

 branches from beneath the initial sessile flower or ses- 

 sile flower-cluster. Such proliferating branches are usually abundantly floriferous. This sort 

 of ecological adaptation is called prophalism (Jepson, Man. 19). Examples of prophalophytes are 

 Oenothera trichocalyx and Navarretia prostrata. 



Typically, Navarretia prostrata is most characteristic of the coast valleys of Southern Cali- 

 fornia. Occasionally there is in a colony partial departure from the usual form. For example, at 

 such a station as National City, the abbreviated main axis may elongate an inch or two, thus lift- 

 ing the primary head off the ground and spacing the lateral secondary radiating branches. In 

 other words this is just the habit simulating that not infrequently found in Navarretia leucocephala 

 of the Great Valley when the reverse conditions occur, that is, when the primary axis in certain 

 individuals of a colony shortens markedly and the lateral branches much exceed it in length 

 (Madera, 8 mi. n. of. Hoover 1253; Modesto, 10 mi. w. of, Hoover 580; Mills sta., n. Sacramento 

 Co., Jepson 15,731). In the broken sequence of moisture and dryness and varying temperatures 

 in a particular season, irregular stimulation of some individuals of Navarretia leucocephala may, 

 perhaps, furnish an explanation of the reason why Navarretia prostrata has sometimes been attrib- 

 uted to the Great Valley (Greene, Man. Reg. S. F. Bay, 246; Jepson, Man. 788). Constant tech- 

 nical differentiae between the two species appear to be lacking; habit simulation is at times obvious. 

 Therefore, it seems better to restrict Navarretia prostrata geographically to coastal Southern 

 California and Monterey Co. Stations are cited as follows: National City, sw. San Diego Co., 

 Cleveland; Wilmington, Nevin; Downey, Davidson; Los Angeles, Gardner; Upland, San Bernar- 

 dino Valley, Parish 11,162 ; Jolon, Monterey Co., Keeh 4- Stocl-well 3225. At the end one needs to 

 hazard that a species so weak technically may need reducing to varietal rank under N. leucocephala. 



Fig. 

 Hook. 



375. Navarretia intertexta 

 a, fl. branch, X 1 ; b, bract, X 



Si/o; c, fl., X 21/0. 



