MEXICAN AND CENTRAL AMERICAN UMBELLIFER^ I45 



Chiapas: about Tumbala, altitude 1200-1650 meters, Nelso7t 3341, 



October 20-29, ^^95? Valley of Comitan, altitude 1740-1950 



meters, Nelsofi 3483, December S-io, 1S95. 

 Guatemala : on mountains near Hacienda of Chancol, altitude 3300 



meters, Nelson 2666, January 2, 1896. 

 Costa Rica: Pittier & Tonduz 1287, August 1889, and 4357, 



August 1891 ; altitude 1355 meters, Tonduz 7689, March 1893. 



21. LEPTOCAULIS Nutt. in DC. Coll. Mem. 5: 39. pi. 10. 1829. 

 A genus of the United States, represented in Northern Mexico by a 



single species", L. echinatus Nutt., which is not endemic. This has 

 not been collected in Mexico for many years, and no Mexican speci- 

 mens are found in the National Herbarium. 



22. AMMOSELINUM Torr. & Gray, Pac. R. Rep. 2: 165. 1855. 

 A genus of southwestern United States, including but two species, 



one of which, A. popei Gray, has been collected once by Palmer 

 near Monterey, Nuevo Leon. 



23. CICUTA L. Sp. PI. I : 255. 1753. 

 A genus widely distributed throughout the northern hemisphere. 

 The single endemic species described below Hemsley referred to the 

 common C. maculata of the United States. In 1SS7, Watson de- 

 scribed a second Mexican species of Cicuta (C. linearifolia)^ which 

 proved to be a Prionosciadium. 



Cicuta mexicana C. & R., sp. nov. 



Apparently robust, 9 to 12 dm. high; basal leaves twice ternate 

 and then bipinnate : leaflets lanceolate, 3 to 7 cm. long, serrate, the 

 veinlets running to the sinuses; umbel with numerous unequal rays, 

 with involucre mostly wanting, and involucel of numerous, rather 

 conspicuous, elongated linear bractlets ; rays (in flower) 4 to 8 cm. 

 long, pedicels very unequal, 2 cm. or less long; fruit very immature. 

 Vera Cruz : Coatzacoalcos, Isthmus of Tehuantepec, Charles L. 

 Smith 1 161, April i, 1895; swamps near Jalapa, altitude 1200 

 meters, Pringle 7708, in 1899. 

 This is undoubtedly the Cicuta referred by Hemsley in Biol. 

 Centr.-A?7ier. to C. 7naculata^ a species whose range seems to be en- 

 tirely north of Mexico. 



24. PIMPINELLA L. Sp. PI. i : 263. 1753. 

 A large genus of world-wide distribution, represented in Mexico by 

 the single peculiar species P. tnexicafia Robinson, Proc. Am. Acad. 

 26: 164. 1891. 



