1923] Ottley: A Revision of the Calif ornian Species of Lotus 191 



Development of the Generic Concept of the Genus Lotus 

 IN Its Kelation to the New World Species 



The American species first described were referred to the Old 



World generic type Lotus. They were L. sericeus Pursh, in 1814, 



and L. suhpinnatus Lag., in 1816. The third species was described 



by W. J. Hooker as L. pinnatus in 1829. Later that same year, 



Bentham redescribed this species and named it Hosackia hicolor 



Dougl. making it the type of the new genus Hosackia. At the same 



time he described two other species for his new genus, Hosackia 



decumhens and Hosackia parviflora, and transferred Lotus sericeus 



of Pursh to Hosackia, assigning to it the binomial Hosackia purshiana. 



In stating his reasons for regarding the American plants as generically 



distinct from the Old World genus Lotus, Bentham says of Hosackia 



hicolor Dougl. 



This plant has much of the habit, as well as the inflorescence and fruit 

 of a Lotus, to which Dr. Hooker. has referred it in the Botanical Magazine; but 

 independently of the characters which may be drawn from the position of the 

 alae and the capitate stigma, the pinnate not ternate leaves, and the absence 

 of the large foliaceous stipule of Lotus — characters which appear to be of 

 importance among most of the Leguminosae * * * perhaps alone suffice for the 

 adoption of the genus HosacMa proposed by Mr. Douglas. 



Bentham found, however, as he became acquainted with an 

 increasingly larger number of American species, that the characters 

 which he had regarded as distinctive for Hosackia did not hold for 

 all; and in 1837, retaining the name Hosackia for eleven species, 

 he referred five {Lj. suhpinnatus Lag., L. macraei Benth., L. 

 micranthus Benth., L. sericeus Pursh, and L.f unifoliolatus Hook.) 

 to the genus LotiLS and created for these the section Microlotus 

 characterized by plants having one-flowered peduncles and exstipulate 

 leaves of three to five leaflets. Bentham and Hooker (Genera 

 Plantarum, 1865) reduced two of these {L. macraei Benth. and L. 

 unifoliolatus Hook.) to synonymy, retained the other three in the 

 section Microlotus of the genus Lotus, and referred twenty -five other 

 American species to the genus Hosackia. 



Torrey and Gray (Flora of North America, 1838) used the name 

 Hosackia for all the American species, as did Gray (Synopsis of the 

 Species of Hosackia, 1863). Watson (Botany of California, 1876) 

 followed Gray in recognizing the genus Hosackia and referred to it 

 all the species belonging to the group under discussion. These three 

 works, however, differ as to the number of sections and as to the 



