48 COXTRIBUTIONS FROM THE ISTATIONAL HERBARIUM. 



Cone scales in vertical series. 



Cone scales with 2 transverse appendages at the apex ; caudex covered with 



persistent petioles 2. CERATOZAMIA. 



Cone scales naked ; caudex naked 3. ZAMIA. 



1. DIOON Lindl. Bot. Reg. 1843: Misc. 59. 1843. 



Pinnae entire 1. D. edule. 



Pinnae spinulose-denticulate. 



Pinnae with numerous teeth on both margins ; trunk 2 to 15 meters high. 



2. D. spinulosum. 



Pinnae entire on the lower margin, with few teeth on the upper margin ; trunk 



short 3. D. purpusii. 



1. Dioon edule Lindl. Bot. Reg. 1843: Misc. 59. 1843. 

 Zamia maeleni Miquel, Linnaea 18: 97. 1844. 



Plaiyzamia rigida Zucc. Abh. Wiss. Akad. Miinchen 4: 23. 1845. 



Dioon imbiicatum Miquel, Wiss. Tijdschr. 1: 36. 1848. 



Dioon anfjustifolium Miquel, Wiss. Tijdschr. 1 : 37. 1848. 



Dioon aculeatum Lem. 111. Hort. Lem. 2: Misc. 91. 1855. 



Dioon edule latipinna Dyer in Hemsl. Biol. Centr. Amer. Bot. 3: 191. 1883. 



Nuevo Le6n, Tamaullpas, San Luis PotosI, and A'eracruz; described from 

 cultivated plants. 



Plants with a trunk 1 to 2 meters high ; leaves 1 to 1.5 meters long, woolly 

 when young, 'with about 200 pinnae, these linear-lanceolate, sharp-pointed; 

 •staminate cones cylindric, 20 to .30 cm. long; pistillate cones ovoid, 20 to .30 cm. 

 long. "Chamal" (Nuevo Leon. Tamanlipas, San Luis Potosi) ; " sotol " (Ta- 

 maullpas) ; "palma de la virgen " (Sinaloa; in market) ; " palma de macetas " 

 (Durango; cultivated). 



The large chestnut-like seeds contain much starch, and are roasted or boiled 

 and eaten. They are a favorite food of bears, peccaries, and domestic swine. 

 A decoction of the seeds is said to be used for neuralgia. The staminate 

 inflorescences are claimed to be poisonous to cattle, causing emaciation and 

 partial paralysis. The plant is often seen in cultivation. 



2. Dioon spinulosum Dyer; Eichl. Gart. Zeit. 1883: 411. 1883. 

 Reported from Veracruz and Yucatan. 



Said to attain a height of 15 meters, although oft^en much lower ; leaves 

 numerous, spreading, 1 to 2 meters long, with very numerous pinnae. 



3. Dioon purpusii' Rose, Contr. U. S. Nat. Herb. 12: 260. 1909. 



In shaded canyons, Puebla and Oaxaca ; type from Tomellin Canyon, Oaxaca. 



Trunk short; leaves numerous, a meter long or larger, stiff, ascending; 

 pinnae 5 to 9 cm. long; staminate cones 15 to 20 cm. long; fertile cones about 

 45 cm. long and 20 cm. thick. "Chamal" (Oaxaca). 



A plant with similar leaves, probably of the same species, has been collected 

 In Tepic. Another similar plant, with glaucous leaves, is in cultivation in 

 Sonora. 



* Named for C. A. Purpus. who has rtiade extensive collections in Mexico in 

 recent years, especially in Baja California, San Luis PotosI, Veracruz, Puebla, 

 and Chiapas. His collections have included many plants previously unknown, 

 most of which have been described by Brandegee. Sets of his collections are 

 in the U. S. National Herbarium. 



