178 PROCEEDINGS OF THE AMERICAN ACADEMY 



diameter; rays elliptic, 3-toothed, 2-3 lines in length. — Alkaline 

 plains, Hacienda de Angostura, San Luis Potosi, June, 1891 

 (n. 3762). 



Plaveria anomala. A glabrous annual, a span high: stem stri- 

 ate-angulate, much branched- leaves linear or lance-linear, grad- 

 ually narrowed to a slightly connate base, acute, 1^—2 inches long, 

 1^-2^ lines wide: heads numerous, aggregated at the ends of the 

 branches in dense corymbs, very small, subtended by minute dark- 

 tipped bracts, 1- (rarely 2-) flowered; the single flower either tubular 

 or ligulate: involucral scales of unequal breadth, lance-linear or 

 oblong, more or less narrowed but obtuse at the apex, persisting in 

 fruit and becoming swollen and bulbous on the back near the base : 

 corollas bright yellow; in the tubular flowers the campanulate 

 throat and spreading limb equalling the tube, the latter hairy on 

 the outer surface; the ligules a line or less in length: achenes 

 oblanceolate, ribbed, black. — Plains, Vanegas, San Luis Potosi, 

 September, 1890 (n. 3669). This interesting plant was first col- 

 lected by Dr. C. C Parry in Northern Mexico, 1878 (n. 31), and 

 again the same year en route from San Luis Potosi to San Antonio, 

 Texas (n. 500) ; but Dr. Parry's specimens were determined (prob- 

 ably by Mr. Hemsley) as F. linearis, Lag. "forma morbida." Dr. 

 Gray noted the specimens as a new species, but appears never to have 

 described them. Mr. Pringle's plants, collected twelve years later 

 and agreeing closely with Dr. Parry's, seem to show that they rep- 

 resent a permanent species, and not merely a casual form. In its 

 very few-flowered heads this species approaches F. repanda, Lag. 



Porophyllum Pringlei. A smooth pruinose annual, l£- 2 feet 

 in height: stem terete, simple below, branching above: leaves 

 elliptic, subentire, with rounded apex and acute base, delicate in 

 texture; the cauline mostly opposite, 1-2 inches long, half as 

 broad, on slender petioles of nearly equal length; the rameal 

 mostly smaller, inclining to be alternate: glands of the leaves 

 few, all marginal, broadly elliptic, light brown: heads rather few, 

 scattered, 9 lines in length, tapering and very acute in bud: scales 

 of the involucre narrow, | of a line in breadth, acuminate, with 

 scarious margins and a single median row of glands : peduncles aris- 

 ing singly: flowers few s about 12, little or not at all exceeding the 

 involucre: corolla tube very slender, about equalling the achene in 

 length; the limb very small, nearly white. — Barranca near Gua- 

 dalajara, September, 1889 (n. 2954) ; also in a similar locality, 

 October, 1891 (n. 5168). This species is near P. Ervendbergii, 



