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. fromEu. 

 " 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. PI. Germ. 



M. prcecox, 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 subdivergent, somewhat hooked 

 at the apex; seeds ovate-reniform." 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. II. 179 



M. intertexta, Willd. 



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

 description see Wood's Bot. and PI. 



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. PL 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, as long as tube ; corolla pale 

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

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

 longitudinal anastomsing nerves." Boiss. PL Or. 



PETALOSTEMON, Michx. 



*P. violaceuS) Michx. PRAIRIE CLOVER. 

 Concord, introduced from Mich, by Minot Pratt. 



