26 MIDDLESEX FLORA. 



M. minima L. 

 Lowell, " dumps ; " Westford, woollen-mill yard (Dr. C. W. Swan) ; 

 N. Chelmsford, wool-waste (Rev. W. P. Alcott). Adv. froniEu. 

 "Peduncles 1-2-flowered, longer than the leaves, shorter than the 

 spiral, sub-globose, spiny, slightly hairy pods ; whorls about 5, 

 loose, veinless, with narrow, obtuse, distichously spiny margin; 

 spines patent, subulate, straight with a hooked point, furrowed on 

 each side ; stipules ovate, shortly denticulate, the upper subentire ; 

 leaves obovate, denticulate; petioles, peduncles and stem pubes- 

 cent." Koch, Syn. Fl. Germ. 



M. proscox, DC. 

 Westford, wool-waste (Dr. C. W. Swan). Adv. from Eu. 

 "Stems prostrate; leaves obcordate, denticulate ; stipules ciliate- 

 dentate; peduncles 1-2-flowered, short; pods spiral, smooth, plane 

 on both sides ; whorls slender, rugose, with thick, nerveless, plane 

 margin, spiny at the sides ; spines subdivergeut, somewhat hooked 

 at the apex; seeds ovate-reniforni." DC Prodr. II. 178. 



M. aculeata, Willd. 

 Westford, wool-waste (Dr. C. W. Swan). 



" Leaves rhombic-ovate, dentate ; stipules dentate ; peduncles about 

 2-flowered; pods spiral, cylindric, flat at the sides; the whorls 

 muricate on the margin." "- Patria ignota.''^ DC. Prodr. 11. 179 



M. inter texta, Willd. 

 Westford, wool-M'aste (Dr. C. W. Swan). Adv. from Eu. For 

 description see Wood's Bot. and Fl. "v 



Trigonella, L. 



"This genus is distinguished from Medicago by the never spirally 

 twisted pod. The species with small, ovate-oblong pods are distin- 

 guished from Melilotus by the beak." Boiss. Fl. Or. 

 T. Cassia^ Boiss. 

 Lowell, waste-heap (Dr. C. W. Swan). Adv. from Asia Minor. 

 "Sparingly hairy; short prostrate stems; leaflets, cuneate-truncate 

 or retuse, toothed at the apex; flowers solitary; lobes of calyx 

 somewhat hairy, linear-lanceolate, i as long as tube ; corolla pale 

 violet li times as long as calyx; pod smooth, cylindrical, scarcely 

 curved, terminating in a beak about i its own length, traversed 

 longitudinal anastomsing nerves." Boiss. Fl. Or. 



Petalostemon, Michx. 



*P. violaceus, Michx. Prairie Clover. 

 Concord, introduced from Mich, by Minot Pratt. 



