32 ERYTHEA. 



In the year 1836 he was sent to Mexico by the London Horti- 

 cultural Society, to collect living plants and seeds, and to make 

 herbarium specimens. He was directed by the Society to devote his 

 attention almost entirely to the elevated regions of Mexico, that is, 

 to the tierrafna, or upper limits of the tierra templada, in order to 

 secure such plants as might be expected to do well in England in 

 the open air, or with slight protection. The Society, at this time 

 and afterwards, was largely interested in the introduction, cultiva- 

 tion, and propagation of hardy or half-hardy trees, shrubs, and 

 herbaceous plants from little-known regions; and through their 

 agency thousands of rare, useful, and ornamental plants were 

 brought into the gardens of England and the continent. 



Hartweg was described by the Society's officers as a "steady, well- 

 informed, and zealous young man," a statement of his abilities 

 succinct enough, and far from being couched in extravagant terms; 

 but that even such a modest recommendation might serve to fore- 

 shadow a very considerable amount of endurance, enthusiasm, and 

 judgment, he abundantly proved during seven years of exploration 

 in Mexico and the tropics of America. 



He landed at Vera Cruz in December, 1836, and journeyed from 

 Mt, Orizaba, near the coast, to the table-lands between San Luis 

 Potosi and Zacatecas, and to the Sierra Madre of Durango. He 

 afterwards proceeded southwards to Morella, the capital of Mecho- 

 acau, and glowingly described the beautiful vegetation of the broken 

 country; its oaks adorned with epiphytes, and its showy fuchsias 

 and rigidellas. Thence he returned to the City of Mexico by way 

 of the plateau of Real del Monte. He next visited Guatemala. 

 It was on this long journey that he took up his headquarters for a 

 time at Oajaca, in southern Mexico, and made excursions in vari- 

 ous directions — one to the north coast across the Cordillera, complet- 

 ing a circuit of six hundred miles; another to the south coast, on 

 which occasion he rediscovered the Hand-tree, Cheiranthodendron 

 pentadadylum, the individual which he found measuring sixty feet 

 in height; and yet another to the wooded districts of Chinantla; 

 after which he resumed his course, skirting the shores of the Pacific 

 for one hundred and thirty leagues. After studying for some time 

 the tropical vegetation of Guatemala and ascending the Volcano de 



