666 Part IV. Chapter 6. 
may be considered the lowest elevation at which the pine trees grow‘), whereas in the north 
the lowest limit of the pine timber is about roo m above sealevel. In many situations in the 
savannas, the air temperature is sufficient to permit the growth of pines, which appear in single 
groups, or in large groves (savannas with pines). 
Dry Tropic Forest Formation. Along and in the neighborhood of the 
Pacific coast, whither the moist air currents from the ocean occasionally im- 
pinge even in the dry season, occur primeval forests, which reach only the 
thickness of the tropic rain forests in the north, where the forest trees assemble 
themselves along the banks of rivers, or rapidly flowing streams. These dıy 
forests differentiate themselves from the tropic rain forest in the north by the 
presence of numerous trees with a periodic leaf-fall, through the extreme 
scarcity of lianes, epiphytes and palms, and through the absence of tree 
ferns ?). 
The relative poverty of undergrowth is a marked feature, and where it is found, it consists 
largely of suceulent plants. Many times the sole undergrowth consists of bromeliaceous plants 
(typically in Salvador where these forests have their most pronounced distribution than in southern 
Honduras). In places, this forest formation merges with the savanna formation, thus constituting 
along the line of tension, a tree savanna, 
Where the rainfall is greater this forest formation grades into the wet forests of the plains 
where, as in southern Salvador, it is impossible to clearly demarcate them. The boundary line, 
however, is well marked where the primeval tropie rain forest comes in contact with savannas, 
or pine ridges, elsewhere the lines of contact are more difficult to establish on account of the 
dovetailing of one formation into another. 
The Chaparral Formation, consisting of a dry forest of small- 
leaved trees of short stature with thorns is widely distributed in considerable 
areas throughout the Guatemalan Region. 
The chaparral vegetation consists of species of Acacia, Crescentia, numerous cacti (Opuntia, 
Mamillaria, Cereus) and in high elevations species of Agave. { 
There is.an arid region supporting purely xerophytic vegetation in the 
central part ofthe country beginning at Gualan, 80 miles (129 km) from Puerto 
Barrios in ’the valley of the Motagua extending to El Rancho 130 miles 
(209 km) from Puerto Barrios, according to W. A. KELLERMAN, thence west- 
ward and north-westward through Salama. Tree cacti of the Cereus, Opuntia 
and Peireskia types are the characteristic forms together with Leguminosae, 
Swretenia mahagoni, Ficus trees etc. The grasses and other vegetation seem 
to be absolutely dead during the dry season, but when the rains begin in 
the spring everything becomes intensely green. At Zacapa, the vegetation is 
of a pronounced xerophytic type, tree cacti are abundant and Acacia- and 
Mimosa bushes are common together with numerous short-stemmed, matted 
grasses,. 
1) SAPPER, K.: Beitr. phys. Geographie von Honduras, see Bibliogr. p. 86; also the important 
paper by O. F. Cook: Vegetation affected by Agriculture in Central America. Bull. 145 U. 8. 
Bureau of Plant Industry 1909. 
2) SAPPER, K.: Beiträge zur physischen Geographie von Honduras p- 149. 
