592 PROCEEDINGS OF THE AMERICAN ACADEMY. 



II. A REVISION OF THE GENUS RUMFORDIA. 

 By B. L. Robinson. 



The genus Rumfordia, originally described by the eldest De Candolle 

 and dedicated to Count Rumford, was founded upon a single species, R. 

 floribunda, a showy-flowered shrub from the uplands of central and 

 southern Mexico. The genus was for more than fifty years believed to 

 be monotypic, but in 1892 Mr. T. S. Brandegee published the descrip- 

 tion of a second and very distinct species, which he had discovered in 

 the mountains of southern Lower California. From 1903 to 1905 Dr. 

 Greenman amplified the records of the genus by characterizing two 

 species from Costa Rica and a pubescent form of the original R.Jiori- 

 bunda. As two more new species of Rumfordia have now been found 

 in a very interesting collection of plants secured by the late E. Lan- 

 glasse", it seems worth while to present here a resume' of the genus as far 

 as it is known to date. The group is notable for its entire freedom from 

 synonymy and nomenclatorial difficulties. Of its members not one ap- 

 pears to have borne any other name than the one here recognized. 



RUMFORDIA DC. (ad equitem clarissimum Benjaminem Thompson 

 comitem de Rumford dedicata). — Capitula mediocria vel majuscula 

 heterogama. Flosculi 9 6-20 liguliferi fertiles ; ligulis ellipticis vel 

 oblongis vel linearibus tenuibus et flavis vel aetate indurescentibus 

 et albicantibus nunc simplicibus nunc obscure bilabiatis. Flosculi 

 disci ca. 10 vel multo numerosiores $ fertiles, corollis tubulosis flavis, 

 tubo proprio gracili pubescenti quam fauces subcylindrici glabriusculi 

 distincte breviore vel eos subaequanti, dentibus limbi 5 brevibus del- 

 toideis. Achaenia obovoidea modice compressa calva glabra conformia. 

 Involucrum duplex, squamis exterioribus herbaceis ovatis vel ellipticis 

 vel oblongo-lanceolatis laxe patentibus, squamis interioribus multo 

 minoribus ovatis vel lanceolatis paleiformibus erectis cucullatis achaenia 

 flosculorum exteriorum amplectentibus. Receptaculum plano-convexum 

 paleiferum. — Prod. v. 549 (1836); Deless. Ic. Sel. iv. t. 30 (1839); 

 Benth. et Hook. f. Gen. ii. 359 (1873) ; Hemsl. Biol. Cent. -Am. Bot. ii. 

 (1881); Baill. Hist. PI. viii. 215 (1886); Hoffm. in Eng. et Prantl, 

 Nat. Pflanzenf. iv. Ab. 5, 230 (1890) ; Brandegee, Zoe, iii. 241, t. 23 

 (1892) ; Greenman, Proc. Am. Acad, xxxix. 99 (1903), xl. 38 (1904), 

 xli. 2G1 (1905). — Frutices vel rarius herbae elatae perennes, caulibus 





