BOTANY. 73 



the apex, tipped with a simple stigma. Achenia pretty numerous, smooth, glabrous ; when 

 mature marked by a few thick and irregular longitudinal ribs ; the style deciduous by an arti- 

 culation. Seed suspended from near the summit. 



" Although so well marked by the characters above citerl, this plant and the two of the pro- 

 posed first section evidently belong to the same genus, and that intermediate between Horkelia 

 and Potentilla. The first section is more like Horkelia, from which the 20 stamens with fili- 

 form filaments (instead of 10 with broad or deltoid filaments) distinguish it. The second, 

 except as to the foliage, resembles Potentilla, but is distinguished by its definite stamens in 

 three ranks, &c. Dr. Torrey indicated the essential characters of this genus several years ago, 

 but allowed the two species then known to him to be provisionally appended to Horkelia. Dr. 

 Newberry '8 discovery, however, renders it necessary to complete the separation. The present 

 name is chosen to commemorate one of the oldest surviving botanists of the United States, the 

 venerable Dr. Eli Ives, formerly professor of materia medica and pharmacy in Yale College, 

 who, although he has published little directly upon botany, has rendered excellent service as a 

 teacher of the science to a long series of pupils." A. Gray. 



Plate XI. Ivesia gracilis. Plant of the natural size. Fig. 1. A flower. 2. A petal. 

 3. Section of receptacle, calyx, &c. 4. Flower spread out flat, to show the insertion and 

 arrangement of the stamens; the ovarian receptacle cut wholly away. 5. A pistil. 6. The 

 receptacle in fruit vertically divided. 7. A ripe achenium. 8. The same vertically divided. 

 All the details more or less magnified. 



Horkelia cuneata, Lindl.; Torr. & Gray, Fl. 1, p. 435. Shores of Klamath lake. 



Horkelia congesta, Hook.; Torr. & Gr. Flor. l,p. 434. Banks of Hat creek, northern Cali- 

 fornia. 



Fragaria Californica, Cham. & Schlecht. in Linnaza, 2, p. 20 ; F. Chilensis, Torr. & Gray, 

 Flor. 1, p. 448, in part. Willamette valley. 



Fragaria Chilensis, Ehrh.; Torr. & Gray, Flor. 1, p. 448. Portland, Oregon ; November 1, 

 in flower. 



Rosa fraxin^efolia, Borr.; Lindl. Bot. Reg., t. 458; Hook. Flor. Bor.-Amer. 1, p. 199. 

 Common in northern California and Oregon. 



Pyrus rivularis, Dougl. in Hook. Flor. Bor.-Amer. 1, p. 203, t. 68 ; Torr. & Gray, Flor. 1, 

 p. 471 ; Nutt. Sylv. 2, p. 22, t. 49. Pit river, northern California. 



Pyrus Americana, DC. Prod. 2, p. 637; Torr. & Gray, I. c. Cascade mountains, 0. T. 



Cerasus mollis, Dougl. in Hook. Flor. Bor.-Amer. 1, p. 169. On Pit river and in Cascade 

 mountains. 



Cerasus demiss a, Nutt. in Torr. & Gray, Fl. \,p. 411. Common in mountains throughout 

 northern California and Oregon. 



Prunus subcordata, Benth. PI. Hartw. No. 1710. Sierra Nevada, near Lassen's butte ; 

 Klamath lakes, August, in fruit ; fruit large, excellent. 



Amelanchier Canadensis, var. alnifolia, Torr. & Gray, Flor. \,p. 473. Amelanchier alni- 

 folia, Nutt. Jour. Acad. Phil. 7, p. 22. 



Chamjecatia foliolosa, Benth. Plant., Hartweg. No. 1712; Torrey, PI. Fremont, p. 11, t. 6. 

 Banks of Canoe creek, July 30, in flower ; a very handsome plant, and well worth an effort for 

 its cultivation. 



CALYCANTHACE^. 



Calycanthcs occidentalis, Hook. & Am. Bot. Beech, p. 340, t. 84. Sacramento valley. 

 10 Z 



