MORNING-GLORY FAMILY. 327 



3. CRESSA L. 



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

 Sepals nearly equal. Corolla white, its tube oblong-campanulate, equaling 

 the sepals; limb 5-parted into lightly eonvolute-imbricate lobes which are some- 

 what indnplicate iu the bud. Filaments filiform, exserted from the throat of 

 the corolla; ovary 2-celled, 4-ovuled. Capsule by abortion often 1-seeded. 

 (Greek Kressa, a Cretan woman.) 



1. C. cretica L. Commonly densely branched from the base, forming 

 low tufted plants 3 to 6 in. high; leaves oblong-ovate, 2 to 4 or 5 lines long, 

 almost sessile; flowers short-pediceled in the axils; sepals oblong-ovate, acute, 

 2 lines long ; corolla-lobes oblong-ovate ; ovary long-hairy. 



Alkaline lands from the Sacramento Valley southward, especially common 

 in the San Joaquin Valley, often covering thousands of acres. May. This 

 plant and several others of the interior plains, such as Sida hederacea and 

 Distichlis spicata, indicate a high percentage of alkali salts in the soils where 

 they grow. 



4. CUSCUTA L. Dodder. 



Annual leafless parasites, destitute of green color, with twining filiform 

 stems. Flowers small, in lateral heads or clusters. Calyx colored like the 

 corolla, deeply 5-cleft. Corolla campanulate or somewhat urn-shaped to short- 

 tubular, with 5 lobes imbricated in the bud, and as many small scales or ap- 

 pendages inserted in the tube below the stamens, or none. Ovary globular, 

 2-celled, 4-ovuled. Styles 2, in ours distinct, persistent ; stigma globose. 

 Capsule 1 to 4-seeded, ours indehiscent. Embryo devoid of cotyledons. The 

 germinating seed produces a twining stem; this becomes parasitic by means of 

 suckers which penetrate the bark of the host. (Derivation doubtful.) 

 Capsule pointed or conical; corolla-tube with fimbriate scales. 



Corolla-lobes J / 2 as long as the cylindrical tube 1. C. subinclusa. 



Corolla-lobes as long as the shallow-campanulate tube 2. C. salina. 



Capsule depressed-globose. 



Flowers in dense globose clusters; scales present 3. C. arvcnsis. 



Flowers in loose cymes; scales none 4. C. calif ornica. 



1. C. subinclusa Dur, & Hilg. Stems commonly stout; flowers 2% to 3 

 lines long, sessile or short-pediceled, at length in large dense clusters % to 1% 

 in. thick; calyx-lobes overlapping, ovate-lanceolate, about !/•> the length of the 

 cylindrical corolla-tube; corolla-lobes ovate-lanceolate, minutely crenulate, 

 scarcely more than % the length of the tube; anthers oblong or oval, nearly 

 sessile ; scales narrow, fimbriate, opposite the stamens but reaching only to the 

 middle of the tube; styles slender, mostly longer than the ovary; ovary capped 

 by the withered corolla. 



Very common on Poison Oak and other shrubs and herbs, often occurring 

 on willows and making thick tangles 1 to 2 ft. across. Calyx sometimes red- 

 dish; lobes of the corolla mostly erect; tube sometimes narrowed above. 



2. C. salina Engelm. Marsh Dodder. Stems slender; flowers V/ 2 lines 

 long; calyx-lobes ovate-lanceolate, as long as the shallow-campanulate tube of 

 the corolla and as the corolla-lobes; these ovate, denticulate, overlapping; 

 filaments about as long as the oval anthers; scales fringed, mostly shorter than 

 the tube, sometimes much reduced and on the base of the tube; stylos equaling 

 or shorter than the ovary; capsule surrounded by the withered corolla, mostly 



led. 

 Very abundant on Salicornia and other saline herbs, entangling them with 



