De 
1911] Robinson, — Erucastrum Pollichii adventive in America 11 
Some five years ago Mr. William Finger sent to the Gray Herbarium 
for identification a Sisymbrium-like crucifer, which he had collected, 
18 October, 1903, along the tracks of a suburban electric line, just 
beyond the city-limits of Milwaukee. On comparison with European 
specimens in the Gray Herbarium the plant was determined by the 
writer as Diplotaxis bracteata Gren. & Godr. At the time there ap- 
peared to be no record of any other American occurrence of this spe- 
cies, and its single appearance at Milwaukee, a manufacturing and 
shipping center, seemed too casual to warrant published record. 
Some weeks ago Miss Martha Louise Loomis of Sherborn, Massa- 
chusetts, sent to the Gray Herbarium for determination another 
specimen of the same species. It was one of two individuals, which she 
had discovered and collected in gravelly soil beside the railroad at 
Sherborn, 4 September, 1910. This second station, at a great dis- 
tance from the first, suggests that the species is likely to turn up else- 
where in America, possibly to spread and become established in the 
manner of its near relatives Diplotaxis muralis (L.) DC. and D. 
tenuifolia (L.) DC. Though the plant is not yet so firmly fixed as to 
justify its inclusion in our manuals, there seem to be grounds for put- 
ting its American occurrence on record and assembling for the con- 
venience of local botanists its rather extended synonymy. From the 
latter it will be seen that recent and excellent European authorities 
are inclined to recognize the validity of the genus Erucastrum and 
maintain it as a convenient disposition for a dubious group of plants 
which, though in most respects similar to Diplotaxis, lack the double 
row of seeds characteristic of that genus. This view being accepted 
and the international rules of nomenclature applied, the species may 
be recorded as follows: 
Erucastrum Porca Schimp. & Spenn. Fl. Frib. iii. 946 (1829); 
Coste, Fl. Fr. i. 80 (1901); Garcke, Fl. Deutschl. ed. 20, 345, f. 1064 
(1908); Schinz & Keller, Fl. d. Schw. ed. 3, 237 (1909). Sisymbrium 
Erucastrum Poll. Hist. Pl. Palat. ii. 284 (1777). Brassica Erucastrum, 
B ochroleuca Gaud. Fl. Helv. iv. 381 (1829). E. inodorum Reich- 
enb. Fl. Excurs. 693 (1830), and Ic. Fl. Germ. ii. t. 89, f. 4428 (1837-8). 
Sisymbrium hirtum Host. Fl. Aust. ii. 261 (1831). Brassica ochro- 
leuca Soy.-Will. Ann. Sci. Nat. ser. 2, ii. 116 (1834). Sisymbrium 
gallicum Schleich. ex Soy.-Will. 1. c., in synon. Diplotaxis bracteata 
Gren. € Godr. Fl. Fr. i. 81 (1847); Rouy € Fouc. Fl. Fr. ii. 44 (1895). 
Brassica obtusangula, var. [8 Pollichii Archang. Comp. Fl. Ital. 45 
(1882), and ed. 2, 267 (1894). Erucastrum bracteatum St. Lag. in 
Cariot, Etude d. Fl. ed. 8, ii. 54 (1889).— Annual, erect or ascending, 
