646 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



1. Spermolepis echinata (Nutt.) Heller, Contrib. Herbarium Franklin 

 and Marshall Col. 1: 73. 1895. 



Leptocaulis echinatus Nutt. ex DC, Prodr. 4: 107. 1830. 



Maricopa, Pinal, Cochise, and Pima Counties, 1,300 to 5,000 feet. 

 Missouri to Louisiana, west to southern Arizona and Coahuila. 



10. AMMOSELINUM 



Plants annual, caulescent, branching, more or less roughened; 

 leaves ternate, then bipinnate, the segments linear; peduncles axillary 

 and terminal, up to 4 cm. long, or none; umbels compound; involucre 

 mostly absent ; bractlets of the involucel few, linear, acute, somewhat 

 callous-toothed, about equaling the pedicels; calyx teeth obsolete; 

 corolla white; stylopodium low-conic; fruit oblong-ovate, 3 to 5 mm. 

 long, somewhat constricted toward the apex, subcordate at base, 

 laterally compressed, covered with callous teeth, the ribs corky, acute 

 to rounded, the oil tubes 3 in the intervals, 2 on the commissure, the 

 seed face concave. 



1. Ammoselinum giganteum Coult. and Rose, Contrib. U. S. Natl. 

 Herbarium 7: 89. 1900. 

 Mesas near Phoenix (Pringle 28, the type collection), Maricopa, 

 Pinal County (Dewey in 1894), Eloy, Pinal County (Peebles et al. 

 6496). Southern Arizona, California, and Coahuila. 



11. CICUTA. Waterhemlock 



Plants perennial from a vertical or horizontal, short or elongate 

 tuberous base bearing fibrous or fleshy-fibrous roots, caulescent, 

 glabrous; leaves 1- to 3-pinnate, the leaflets linear-lanceolate to ovate- 

 lanceolate, distinct or some of them confluent, remotely to coarsely 

 serrate or incised; peduncles exceeding the leaves; umbels compound; 

 involucre of few bracts or none; bractlets of the involucel several, 

 ovate-lanceolate to linear, acute to acuminate; calyx teeth evident; 

 corolla white or greenish white; stylopodium low-conic; fruit orbicular 

 to oval, 2 to 4 mm. long, slightly compressed laterally, definitely 

 constricted at the commissure, the ribs low, broad and corky, wider 

 than the reddish-brown or homochromous intervals, the oil tubes 

 solitary in the intervals, 2 on the commissure, the seed face concave, 

 plane, or convex. 



Plants violently toxic to warm-blooded animals, especially the roots 

 and young growth. No antidote is known, but in human beings the 

 use of emetics has proved effective. Symptoms are vomiting, colicky 

 pains, staggering, unconsciousness, and convulsions. The poisonous 

 principle, cicutoxin, affects the nerve centers. These plants should 

 be eradicated from ranges, as they have caused the loss of much live- 

 stock. 



1. Cicuta douglasii (DC.) Coult. and Rose, Contrib. U. S. Natl. 

 Herbarium 7: 95. 1900. 



? Slum (?) douglasii DC., Prodr. 4: 125. 1830. 

 Cicuta occidentalis Greene, Pittonia 2:7. 1889. 

 Cicuta grandifolia Greene, Leaflets 2: 24. 1909. 



Apache, Greenlee, and Coconino Counties, 6,000 to 9,000 feet, 

 wet ground, type of C. grandifolia from Mormon Lake (Pearson 140). 

 Montana and Alaska to Arizona, California, and Chihuahua. 



