150 GAMOPETALOUS EXOGENS 



but bluish-green, the Under surface densely clothed with a -white tomentum. 

 Heads of flowers small, in compact axillary and terminal clusters ; involucre some- 

 what ventricose, lanuginous at base ; scales smooth ; florets white, with a minute 

 purplish limb. 

 Hob. Dry, open woods ; clearings, &c. : frequent. Fl. July. Fr. Aug. 



Obs. Further observation has led me to doubt whether this 

 species be really perennial. As TORREY and GRAY remark, it cer- 

 tainly has the appearance of an annual. 



214. AtfTEWMA^RIA, Gaertn. 



[The sterile pappus resembling the Antenna of some insects.] 

 Heads many-flowered, dioicous or nearly so ; pistillate florets very 

 slender. Akenes oblong; pappus in a single series, filiform in the 

 fertile heads, clavate in the sterile ones. Receptacle flat, or convex, 

 not chaffy. Perennials: leaves sessile, entire; heads corymbose; 

 involucre dry and scarious, often pearly white; florets yellowish. 



1. A. margaritaeea, R. Br. Stem erect, sub-simple, corym- 

 bose at summit; leaves lance-linear, lanuginous above, tomentose 

 beneath ; involucral scales obtuse, pearly white. 



Gnaphalium margaritaceum. L. Fl. Cestr. ed. 2. p. 494. 

 PEARLY ANTENNARIA. 



Stem 1 to near 2 feet high, leafy and hoary-tomentose. Leaves 2 to 4 inches long. 

 gublinear, acuminate, narrowed at base. Heads of flowers rather large, roundish- 

 ovoid, crowded in a terminal corymb ; disk tawny ; receptacle flat, pitted. 

 Hob. Slaty hills, near West Chester : rare. FL Aug. Fr. Sept. 



Obs. This species so remarkable for its beautiful pearly heads 

 is occasionally found on our dry hills ; but, to me, it has the ap- 

 pearance of a stray plant among us. 



2. A. plantagtnif dlia, Hook. Stem simple, with procumbent 

 runners at base ; radical leaves spatulate, or elliptic and 3-nerved ; 

 corymb clustered; involucral scales greenish. 



Gnaphalium dioicum, and var. L. $ Fl. Cestr. ed. 2. p. 494-5. 

 PLANTAIN-LEAVED ANTENNARIA. White Plantain. Cat-foot. 



Stem 2 or 3 to 8 or 10 inches high, hoary with a bluish tinge, often with 2 or 3 

 procumbent offsets from the base, which are nearly as long as the upright scape- 

 like stem. Radical leaves 1 to 2 or 3 inches long, obvate-spatulate, or oval and 

 strongly 3-nerved, narrowed to a margined petiole ; stemleaves small, lanceolate. 

 Heads of flowers few (3 to 6 or 8), oblong or subturbinate, in a dense terminal 

 cluster. Receptacle convex, pitted. 

 Hob. Sterile knolls, in low grounds : frequent. Fl. April. Fr. May. 



Obs. This species, as now constituted, certainly presents two 

 strongly marked varieties, one of which nearly approaches the A. 

 dioica, of Europe, in appearance. 



215. FIL.A V GO, Tournef. 



[Latin, Filum, a thread; from the cottony hairs that cover it.] 

 Heads many -flowered ; central florets apparently perfect, but abor- 

 tive, the others pistillate. Akenes oblong; pappus of the central 

 florets capillary, of the outer ones mostly wanting, or caducous. 

 Receptacle columnar or turbinate, naked at summit, chaify at base, 



