United Cordilleran Region. 655 
is, however, quite similar on the two mountains, the lowest consisting‘ of laurels, 
pines and cedars, the middle of firs and the highest of pines. 
The Coniferous Forest Formation grows more stunted until the limit 
of arborescent vegetation is reached at 13,123 feet (4,000 m). There, in the 
Alpine Formation at 13,200 feet, HEILPRIN found a veritable garden of 
plants, including Caszilleja tolucensis , Echeveria gibbiflora, Ageratum arbutı- 
folium, Chionolaena, Phacelia pimpinelloides, while from the rock-fissures 
protruded tufts of Asplenium trichomanes var. majus. Other plants accredited 
to the summit of Ixtaccihuatl are Draba aretoides, Lupinus vaginatus, Oenothera 
tetraptera and Senecio salıgnus. 
Toluca. This mountain (15,091 feet) ranks fourth in point of altitude 
within Mexico. It rises by easy slopes and terminates in a vast bowl of a 
crater, its figure being a truncated cone, much depressed. The rim of the 
crater is ragged, showing several prominent peaks. Its southern slopes fall away 
rapidly to the tierra caliente and its middle slopes are covered with evergreen 
forests. Above the timber line grassy slopes extend up to the rim of the 
crater. The pine forest on this mountain, as before mentioned, consists of 
Pinus Montezumae with Abies religiosa in the cool wet ravines. — Above the 
timber-line according to PRINGLE') are found Eryngium proteaeflorum, 
Senecio Halleri (in mats), Castilleja densa (in mats), Festuca livida, F. ovina, 
Trisetum tolucense, Agrostis virescens, Calamagrostis orizabae and a variety of 
Deschampsia caespitosa, while the absence of sedges is noteworthy. On the 
coldest steeps just under the summit, Musenium alpinum forms a dense sod in 
patches several feet broad: Halenia crassiuscula groWS sparsely and Draba 
Jorullensis more commonly. Gnaphalium lavandulaceum (= Chionolaena lavan- 
dulifolia) is a shrubby species on the summit ledges. 
The oval crater of Toluca, a mile wide and two miles in 
five small lakes in its bottom. In the soft, bare soil on the margins of the lakes, 
Calandrinia acaulis are common. On wet bottoms Alchemilla pinnata forms little patches of 
green, Oreomyrrhis andina (= O. andicola) forms mats, while Dissanthelium sclerochloides 
grows in scattered tufts an inch or two in height. Draba tolucensis oceurs on the moist gravel, 
while in the shelter of rocks detached from above are found Gnaphalium popocatspecium. On 
the slopes above the lakes grow Plantago linearis and an Erysimum. ee 
The following plants are accredited to Toluca: Draba tolucensis (8 —14,000 feet), Erysimum 
macradenium (12—13,000 feet), Cerastium andinum (13,000 feet), Arenaria bryoides (14—15,000 feet), 
ranium potentillaefolium (9—10,000 feet), Lupinus bimaculatus (12,000 feet), L. montanus 
(9—10,000 feet), L. vaginatus (12,000 feet), Ribes jorullensis (L0—12,000 feet), Tauschia eg 
(10,500 feet), Senecio procumbens (10—11,000 feet), Cnicus nivalis (11,400 feet) and Castilleja 
tolucensis (14,200 feet). 
length from east to west has 
rosettes of 
olima. Twin peaks, known respectively as the Nevado de Colima and 
the Volcan de Colima, rise from a plateau covered with agaves, opuntias, 
Argemone mexicana, Asclepias curassavica and other plants to an elevation of 
approximately (in the case of the Nevado) 14,350 feet. A scattered forest 
RE 
1) PRINGLE, C. G.: Notes on Mexican Travel: see Bibliogr. P- 85. 
