Culture of the Sweet Pea 665 



I. Habit climbing, leaves tendril-bearing — (Continued). 



FF. Stipules narrow — (Continued) . 

 L. venosus Mulil. 

 L. longipes White. 

 L. graminifolius White. 

 L. Macraei Hook. 

 EE. Plant densely silky villous all over. 

 L. litoralis. 

 AA. Clymenum. 



L. diffusus. 



L. clymenum, L. 



L. articulatus L. 



II. Plant erect or nearly so, tendrils wanting or much reduced. (Orohiis.) 

 A. Peduncles 2 -several-flowered. 

 B. Flowers white or yellowish. 

 L. montanus Bernh. 

 L. Arizonicus Britton. 

 L. Cusickii S. Watson. 

 L. obovatus Torr. 

 L. rigidus White, 

 BB. Flowers purple. 



C. Leaflets 5-7 pairs. 

 L. ornatus Nutt. 

 L. Nuttallii S. Watson. 

 L. niger Bernh. 

 L. Oregonensis White. 

 L. vernus Bernh. 

 CC. Leaflets 1-2 pairs. 



L. bijugatus White. 

 AA. Peduncles i -flowered. 

 L. Torreyi A. Gray. 



Previous to White's monograph only two attempts had been made 

 to enumerate the species of the genus. The first was by Alefield (Bon- 

 plandia, June, i860), who placed all the American species in the genus 

 Orobus; the second attempt was by Watson (Amer. Jour. Sci., Feb., 1876), 

 who enumerated thirteen species.* 



* Mention should be made of the more recent monographs on the genus La'.hyrus, namely: 

 Uber einige Orobus-Arten und ihre geographische Verbreitung. Series I Lutei. Ein Beitrag 



zur Systematik dor Viceen. Von Dr. Karl Fritsch. Sitzber. K. Akad. Wiss. (Vienna), Math. Naturvv. 



Kl. CIV Band (1895). 



Uber einige Lathyrus-Arten aus der Section Eulathyrus und ihre geographische Vcrbreitung. 



August Ginzberger. Sitzber. K. Akad. Wiss. (ViennaJ, Math. Naturw. Kl. CV Band (1896), pp. 281- 



353, plates and maps. 



