THISTLE FAMILY. 793 



Silphium asperrimum Hook. C'ouip. Bot. Mag. 1 : 99. 1835. 



EOUGH-LEAF KoSUs'WEED. 



Sil2)hhim radula Niitt. Trans. Aui.Phil. Soc. 7 : 341. 1831. 



S. scaherrimnm var. Toir. & C4rav, Fl. N. A. 2 : 279. 1842. 



Gray. Sy:i. Fl. N. A. 1, pt. 2 : 240. ' Coultt^r, Coutr. Nat. Herb. 2 : 205. 



Caroliuiau and Louisiauiau areas. Southern Arkansas, Texas, and Louisiana. 



Al.-vba.aia: Mouutain region. Grassy glades; dry borders of lields. Clay County, 

 Mount Olive. 1,500 feet altitude. .Inly, August; frequent. 

 Ty]ie locality : "' Covington," Louisiana {Dnimtitond). 

 Herb. Gaol. Surr. Herb. Mohr. 



Silphium .scaberrimum Ell. Sk. 2 : 466. 1824. Scabkous Rosixweed. 



Ell. vSk. 1. c. Gray, Syn. Fl. N. A. 1, pt. 2 : 240. Coulter, Coutr. \at. Herb. 2 : 205. 



Carolinian and Louisiauian areas. Western Georgia to Louisiana, Arkansas, and 

 Texas. 



Alabama: Central prairies. Upper division Coast Pine belt. Prairies, Wilcox 

 County? {Buckleji). Monroe County, Claiborne. Lee County, Auburn (Baker cj- 

 Earle). Etowah County, Gadsden (rr. ii'. Faseii). .Inly; infrequent. 



Type locality: "Grows in the western districts of Georgia." 



Herb. (ieol. Surv. Herb. Molir. 



Silphium mohrii Snuill. Bull. Torr. Bot. Club. 24 : 493. 1897. Muhr's Rosixweed, 



Perennial, coarse, very hispid throughout with shaggy hairs. Stem erect, 2| to 3^ 

 ft. tall, simple below, branched above, tinely-channeled in age; leaves alternate, 

 ovate-lanceolate, or narrowly ovate-lanceolate, or normally ovate, 2 to 6 in. long, 

 acuminate at the apex, remotely serrate with prominent teeth, except near the 

 base or apex, sessile or nearly so; heads li t<> If in. broad, pediceled; in\olucres 

 broadly campanulate, the bracts lanceolate to ovate-lanceolate, 4 to 7 lines long, 

 acute or somewhat acuminate; corollas about 4 mm. long, the segments ovate, rather 

 obtuse; rays yellow, elliptic-oblong, 5 to 7 lines long, nndulately 3-toothed at the 

 apex; achenes obovate, more or less constricted at both ends, about 3 lines long, 

 winged. Plate XII. 



Exposed rocky declivities. Cullman County. 



A very distinct si)ecies of the much confused genus Silphium, related to what I 

 understand as ^. aspernmum Hook., hitherto called S. scaherrimxvi. It can easily be 

 distinguished by the copious shaggy pubescence which clothes the foliage up to the 

 flowers. The peculiarly toothed leaves with their less rounded bases and the smaller 

 heads with their narrow bracts and shorter rays are additional diagnostic charac- 

 ters. 



"The species is named in honor of Dr. Charles Mohr." 



Carolinian area. Tennessee {Gatthigtr). 



Alabama: Mouutain region. Exposed rockv declivities. Cullman Conntv. Octo- 

 ber, 1894. Rare. 



Type locality: "In dry or rocky soil, Cullman. Alabama, October, 1885." 

 Herb. Geol. Surv. Herb. Mohr. 



Silphium gatesii sp. nov. 



Stem 2A to 3 feet high, terete, hispid pilose throughout with long white hairs jointed 

 above the inflated papillose base, above the middle more or less covered by short flat 

 tawnj- hairs forming on the upper part of the stem and the branches a close tomeu- 

 tnm ; leaves all alternate, acntish, scabrous abo\ e, paler and less harsh beneath, the 

 radical and lower cauline leaves 6 to 8 inches long, + to | inch wide, narrowed at the 

 base into a slender winged petiole one-third of the length of the sparsely sinuate- 

 dentate leaf blade, the upper sessile with a more or less cordate' base, sparsely den- 

 ticulate or entire ; corymbose branches erect-spreading ; flowering heads more or less 

 numerous, large; involucral bracts tomentose-hairy on the outside, scabrous-hirsute 

 above, hispidulous-ciiiate, oblong-acute, the outer longer then the disk; rays nearly 

 1^ inches long, golden yellow ; achenes obo\ <ate, rather oblong, narrow-winged, 

 slightly emarginate, teeth minute or wanting. Plate XIII. 



Resembles narrow-leaved forms of <S. rts/er(.sc/(s, from which it is distinguished at 

 once by the peculiar pnbesceuce, the thinner narrower lea\ es, and the oblong-ovate 

 achenes almost or entirely destitute of teeth. TheTe is a form with broad leaves and 

 wing. 



Named in commemoration of Hezekiah Gates of Mobile, one of the earliest contrib- 

 utors of Alabama plants to Torrey and Gray's Flora of North America, to whom Dr. 

 (iray dedicated his genus Gatesia, a name found untenable and lately replaced by 

 Yatesia. 



Carolinian area. 



