428 Karl M. Wiegand and Arthur J. Eames 



2. T. porrifolius L. Salsify. Vegetable Oyster. Oyster-plant. 



In situations similar to the preceding, but in heavier soils ; frequent, and widely 

 distributed. June-July. 



In the Cayuga Lake Basin, most abundant about Ithaca. 



Ont. and Minn, to B. C, southw. to Ga., Nebr., and Calif. Escaped from 

 gardens, and more or less naturalized. Native of Eu. 



A form resembling T. porrifolius, but with brown flowers, occurs frequently 

 on East Hill, Ithaca. This is apparently a hybrid with T. pratcnsis. 



43. Chondrilla (Tourn.) L. 

 1. C. juncea L. Skeleton-weed. Gum Succory. 



Dry gravelly knolls ; rare. Aug.-Sept. 



On a knoll s. of Mud Pond, McLean Bogs, 1917, still persisting. 



N. Y. and Del., to Md. and Va. Naturalized from Eu. 



44. Taraxacum (Haller) Ludwig 



a. Leaves shallowly divided ; heads 3-5 cm. in diam., golden yellow ; achenes olive- 

 green or brownish. 1. T. officinale 

 a. Leaves deeply divided ; heads 2-3 cm. in diam., sulphur yellow ; achenes reddish. 



2. T. laevigatum 



1. T. officinale Weber. (Doubtfully T. vulgarc (Lam.) Schrank.) Common 



Dandelion. 



Roadsides and fields, in rich soil ; common. May-June, and sporadically until 

 frost. 



Most abundant in the heavier soils of the basin, and in clay. 



Probably native in northern N. A., but now a naturalized weed from Eu. through 

 the greater part of N. A. Found also in Asia. 



Taraxacum is in the list of nomina conscri'anda of the International Code. 



2. T. laevigatum (Willd.) DC. (See Bot. Gaz. 70:350. 1920. T. erythrospermum 



of Gray's Man., ed. 7.) 



In more gravelly or sandy and less fertile soils than the preceding, especially in 

 lawns ; frequent. May-June, or later. 



Common on lawns and banks on C. U. campus ; distribution elsewhere not 

 determined. 



Me. to Ont. and Alberta, southw. to Pa., 111., and Wyo. Naturalized from Eu. 



45. Sonchus (Tourn.) L. 



a. Heads large, 4 cm. in diam., deep yellow; perennials, with creeping rootstocks. 

 b. Involucre and peduncles glandular-setose. 1. S. arvensis 



b. Involucre and peduncles glabrous. la. S. arvensis, 



var. glabrescens 

 a. Heads smaller, 1.2-2.5 cm. in diam., pale yellow; annuals. 



b. Leaves runcinate-pinnatifid, soft-spiny or unarmed ; achenes longitudinally 



striate and cross-wrinkled. 2. S. oleraceus 



b. Leaves pinnately lobed or undivided, densely spiny-toothed ; achenes ribbed, 

 otherwise smooth. 3. S. asper 



1. S. arvensis L. Field Sow Thistle. 



A weed in rich cultivated or waste places and on shores, often in heavy clay 

 soils; frequent. July-Sept. 



