90 PLANTS 'WRIGHTIAN^. V. 



263. Machjeranthera tanacetifolia, Nees, Ast. p. 224; DC. Prodr.5.p. 262; 

 Hook. Bat. Mag. t 4624. Aster tanacetifolius, H. B. K. ! Nov. Gen. Sf Sp. 4. p. 

 95. A. chrysanthemoides, Willd. in Spreng. Syst. 3. p. 538. Chrysopsis (Pappo- 

 chroma) coronopifolia, Nutt. in Jour. Acad. Philad. 4. p. 34. Dieteria coronopifo- 

 lia, Nutt. in Trans. Amer. Phil. Sac. 7. p. 300 ; Torr. Sf Gray, Fl. I. c. Valley of 

 the Rio Grande, New Mexico, and on the Pecos ; Sept. (San Antonio de las Alan- 

 zanes, Mexico, Gregg.) — Humboldt found the plant growing in the Botanic Gar- 

 den at Mexico ; and Nees founded on it his genus Machseranthera (so named from 

 the lanciform tips of the anthers, which are just the same, however, in most Asters) : 

 but it has not been identified until the present year, when Sir William Hooker has 

 figured under this name specimens raised in the Eoyal Botanic Gardens at Kew, 

 from Mr. Wright's seeds. He did not observe, however, that it is the same as the 

 well-known Dieteria coronopifolia, Nutt. (as I had determined from the specimen in 

 the herbarium of the Paris Museum), probably because the specimen figured has 

 all the upper leaves simply pinnatifid : but similar wild ones have all the lower 

 leaves bipinnately parted. Kunth described the rays as white: Nees had remarked 

 that they were purplish in the dried specimen preserved in the herbarium of Will- 

 denow ; and Gregg notes that they were pale purple in his Mexican specimens. In 

 Texas, and in the cultivated plant, they are usually deep violet, and are quite showy. 

 It is not " suffruticose," although the stems become somewhat indurated ; but the 

 root is biennial or annual. — The older name must replace Nuttall's Dieteria. 



271. M. PARViFLORA (sp. nov.) : glabra, subviscosa; caule ramosissimo; foliis 

 parvis pinnatilobatis lobisque utrinque 3-5 sublinearibus ; involucri squamis 

 2 - 3-serialibus lineari-oblongis acutiusculis disco brevioribus; acheniis sericeis; 

 pappo corolla disci breviore. — Along the Rio Grande, New Mexico; Sept. — Stems 

 a foot or so in height, from an annual root. Cauline leaves half an inch long, 

 those of the branches smaller ; the lobes a line or less in length. Heads three lines 

 in diameter. Rays three lines long, purple. Pappus soft, not very copious ; that of 

 the ray rather shorter than that of the disk. — Very much resembles Psilactis Coul- 

 ter! ; but the leaves are pinnatifid, the achenia are silky- villous, and the pappus al- 

 ways present in the ray. 



264. Aster multielorus. Ait. ; Torr. Sf Gray, Fl. 2. p. 125. Valley of the Rio 

 Grande, New Mexico, and plains at the base of the Guadalupe Mountains ; Sept. 

 Dr. Gregg collected it in Mexico, below Saltillo. — To this species belongs A. hebe- 

 cladus, DC, and A. scoparius, DC, established on specimens from Berlandier's 

 collection. 



•\ A. spiNosus, Benth. PI. Hartw. p. 20. Banks of the Rit Grande below El 

 Paso. Dr. Gregg gathered it at Saltillo. 



265. A. DiVARicATUs, Torr. ^ Gray, I. c. Along the Rio Grande, New Mexico. 



266. Erigeron modestum, Gray, PI. Fendl. p. 68, Sf PI. Lindh. p. 220, excl. 

 syn. Distasis modestse, DC On the San Felipe ; July. Also in the coll. of 1851.* 



* De Candolle's Erigeron ? (Pterigeron) decurrens belongs to the tribe Cynarece, in which, with a 

 second and larger-flowered species from tropical New Holland, it forms a new genus. 



