126 CONVOLVULACEAE 



solitary, short-pedicellate, in axils of uppermost leaves; sepals hirsute or almost 

 pilose below, with often recurved herbaceous and spreading tips, increasingly prom- 

 inent in fruit; corolla-tube usually white, the limb light blue, purple or rose; cap- 

 sule 6 lines long. 



A garden annual from Mexico, sparingly escaped, 5 to 2000 feet : coastal South- 

 ern California. Sept.-Jan. 



Locs. — Arlington, Riverside Co., Gordon Surr; Santa Catalina Isl. (Field Mus. Nat. Hist. 

 Bot. 5:201). 



Refs. — Ipomoea hederacea Jaeq., Coll. 1:124 (1786), "in America torrida"; Edwards, Bot. 

 Reg. t. 85 (1815). ConvolvulusnWL.; Curtis, Bot. Ma^. t. ISSS (1793). I. nil Suth and I. scabra 

 Porsk., aec. House; Bailey, Cyclop. Hort. 2:1659 (1930). I. hirsutula Jepson, Man. 779 (1925), 

 in part. 



2. I. purpurea Roth. Common Morning-glory. Herbage usually sparingly 

 pubescent; leaf -blades cordate, abruptly acute, 1 to 3 inches broad, undivided; 

 flowers in clusters of 2 or 3 on peduncles 1 to 4 inches long, axillary, well distributed 

 along the stem; sepals sparingly hirsute, gradually narrowed upwards to an acute 

 tip, little enlarged in fruit; corolla as in last; capsule globose, 3 to 4 lines long. 



Native of Mexico, an occasional garden escape, 5 to 1000 feet: a few scattered 

 localities, chiefly about the larger cities. Aug.-Sept. 



Locs. — Suisun, if. .4. Waller 984; Los Angeles (Zoe 1:56) ; San Diego Co. (Syn. Fl. 2:210). 



Refs. — Ipomoea purpurea Roth, Bot. Abh. 27 (1787) ; Dav. & Mox., Fl. S. Cal. 283 (1923). 

 Convolvvlus purpureus L., Sp. PI. ed. 2, 219 (1762), "habitat in America." I. hirsutula Jepson, 

 Man. 779 (1925), in part. 



4, CRESSA L. 



Low eanescent perennial herb with erect or diffuse non-twining stems. Corolla 

 white, its tube oblong-campanulate, equaling the sepals; limb 5-parted. Filaments 

 subulate, exserted from the throat of the corolla. Ovary 2-celled, 4-ovuled. Styles 

 2, distinct; stigmas capitate. Capsule by abortiou often 1-seeded. — Species 1, all 

 continents. ( Greek Kressa, a Cretan woman. ) 



1. C. cretica L. var. truxillensis Choisy. Alkali Weed. Commonly densely 

 branched from the base, forming low silvery tufts 3 to 10 inches high; leaf -blades 

 oblong-ovate, 2 to 4 or 7 lines long, almost sessile; flowers short-pediceled in the 

 axils; sepals oblong-ovate, acute, 2 lines long; corolla 3 lines long, its lobes oblong- 

 ovate, about 1 line long, hairy outside or even comose; summit of ovary long-hairy. 



Alkaline vallej's and deserts and coastal marshes, 10 to 100 (or 5000) feet: 

 throughout California. "West coasts of North and South America. Apr. -Sept. 



Tax. note. — The variety truxillensis with its pedicellate flowers, spicately distributed at ends 

 of brancUets, and its oval leaves, sessile by a narrow base, is amply contrasted with the typical 

 plant of the Mediterranean region, whose sessile flowers are capitately congested at the ends of 

 the branchlets, and whose ovate leaves (averaging about 2 lines long and very numerous) are 

 sessile by a broad base. Our plant is very abimdant on plains of the San Joaquin Valley, often 

 covering thousands of acres. Sometimes broad areas of it do not flower or only rarely. By ranch- 

 ers, especially where it is a pest in orchards, it is sometimes called White Weed. 



Locs. — Honey Lake Valley, Lassen Co., Davy 3395; Vacaville, Solano Co., Jepson 14,499; 

 Bolsa near Hollister, Jepson: Palo Pricto Pass, se. San Luis Obispo Co., Jepson 15,887; San Mi- 

 guel Isl. (Pitt. 1:80); Oxnard, Ventura Co., Condit; Santa Catalina Isl. (Zoe 1:142); Long 

 Beach, Parish ; Newport Bay, Booth 1052 ; Coronado, San Diego Co., If. F. Spencer; Colorado 

 River opp. Cibola, J. Grinnell. 



Refs. — Cressa cretica L., Sp. PI. 223 (1753), type loc. Crete. Var. truxillensis Choisy; 

 DC, Prod. 9:440 (1845). C. truxillensis H.B.K.. Nov. Gen. & Sp. 3:119 (1818), type loc. Truxillo, 

 Peru. C. cretica Jepson, Fl. W. Mid. Cal. 388 (1901), cd. 2, 327 (1911), Man. 780 (1925). C. val- 

 licola Hel., Muhl. 8:140, pi. 17 (1913), type loc. San Jose, Heller 893Ca. 



5. CUSCUTA L. Dodder 



Annual leafless parasites, essentially destitute of green color. Stems twining, 

 filiform, white to golden yellow. Flowers small, usually abundant, in lateral heads 

 or clusters. Calyx colored like the corolla, deeply 5-cleft. Corolla campanulate or 



