1898.] NATURAL SCIENCES OF PHILADELPHIA. 413 



No. 6,472. Named in honor of Jesse Moore GreenmaD, of the Gray 

 Herbarium, Cambridge, Mass. 



243. Agave Americana Linn. Sp. PI., 323. 



A plant extensively cultivated throughout Mexico for its fibre 

 and for the juice which yields, upon fermentation, the national bev- 

 erage, pulque. 



244. Taxodium mucronatum Tenore in Ann. Sc. Nat. ser. Ill, xix, (1S53), 355. 



A tree found reaching gigantic girth in several parts of Mexico. 

 The grove of Mexican cypresses below the Castle of Chapultepec 

 being noted for the size of the individual species composing it. Two 

 notable trees are found in it, one 19} feet in diameter, the other, the 

 tree of Montezuma, 14 feet in diameter. Another gigantic specimen 

 is found at Tule on the road from Oaxaca to Guatemala, circumfer- 

 ence, five feet from ground, 146 feet; longest diameter, 40 feet; 

 shortest diameter of the trunk, 20 feet. This tree was also met with 

 at Las Canoas on the Tampico branch of the Mexican Central Rail- 

 road. 'Ahuehuete." , 



245. Zea Mays Linn. X Euchlaena Mexicana Schrad. Zea Mays Linn., Sp., pi. 971. 

 Euchlaena Mexicana Schrad. Ind. Sem. Hort. Gotting (1832). — Cf. Linnaea 



viii (1833) Litt. 25. 



The hybrids of these two plants throw considerable light upon the 

 origin of our cultivated maize. I would refer the student to several 

 papers upon this subject by the writer, as follows: 



1. Maize: A Botanical and Economic Study. Contrib. Botan. 

 Lab. University of Penna., I, pp. 75-202, with 4 plates. A Spanish 

 translation of the entire paper appeared in Mexico, entitled "El 

 Maiz : Estudio Botanico y Economico" (1894), pp. 164. 



2. Fertile Crosses of Teosinthe and Maize. Garden and Forest, 

 IX, p. 522. 



3. Notes on the Hybrid of Maize and Teosinthe. Garden and 

 Forest, X, p. 48. 



4. The Uses of Plants Among the Ancient Peruvians. Bull, of 

 the Museum of Science and Art, University of Penna., I. 



