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288 NOTES OF A BOTANIST CHAP.
3000 feet, and extends thence to the very snow-line, going through
more phases in external appearance than I know in any other
genus.
Composite, 3. So long as I herborised only in the plains, I
could never understand how Humboldt had assigned so large a
proportion of equinoctial vegetation to Composite, for, from the
mouth of the Amazon to the cataracts of the Orinoco and the foot
of the Andes, with the exception of a few scandent Vernoniae and
Mikaniae, and of a few herbs on inundated beaches of the rivers,
the species of Composite that exist are weeds, common to many
parts of tropical America, nor did I meet with more than one
arborescent Composita ( Vernonia polycephala, DC.) in the whole
of that immense area. But in ascending the Andes, from 1200
feet upwards, Composita? increase in number and variety at every
step, and include many arborescent species. About midway of
the wooded region, and especially in places where the trees form
scattered groves rather than continuous woods, Compositae are
more abundant than any other family, both as trees and woody
twiners, and in the latter form extend nearly to the limit of
arborescent vegetation, especially as species of the fine genus
Mutisia ; while on the frigid paramos no frutescent plants ascend
higher than the Chuquiraguas and Loricarias, and as alpine herbs,
the Achyrophori, Werneriae, etc., reach the very snow-line. In
the Red Bark woods Composite are plentiful, and I should estimate
the number of species at near 50. The trees of this order
are chiefly Vernoniae, and they abound most in deserted clearings.
During my stay, a plot was again brought under cultivation which
had remained desert for twelve years, during which period it had
become so densely
slender white stems
and equably clad with a Vernonia, whose
had reached a height of 40 feet, that at a
distance it looked like a plantation. Many of the woody twiners
are Compositae, chiefly Senecionidae, and as herbaceous or suffruticose
twiners there are several Mikaniae. The young shoots of a
species of Mikania bear very large cordate leaves, usually white
over the veins and purple or violet on the whole under-surface.
. . . Among shrubby Compositas I noted some Eupatoria and
two Baccharides, but no Barnadesia ; nor among herbs any
Gnaphalium, although on the eastern side of the Cordillera the
two latter genera descend nearly to 3000 feet. Tessaria legitima,
DC., is abundant by the Rio San Antonio. I have come on
this tree in the roots of the Cordillera on both sides, by all the
streams which have open gravelly or sandy beaches laid under
water by occasional or periodical floods.
Apocynetz, 2. One Peschiera and one Echites. This order
rarely ascends up out of the hot region in the Andes, and in
temperate region
the
I have seen only a single species.