THE AMERICAN BOTANIST. 
29 
States and known as long, gray or Spanish moss. It is not a 
moss, however, for it flowers and fruits abundantly. Further 
south there are nearly a thousand species, but comparatively 
few of them moss-like. The well-known pineapple is a 
species of this group and a large number of the other species 
are fashioned on the same plan. On this account they are 
usually known as wild pines. The common pineapple grows 
in the soil, but many of the others are found high up on the 
branches of other trees. Unable in such positions to draw 
a supply of nitrogen from the soil, the sheathing leaves form 
resen^oirs in which drowned insects and decaying vegetation 
collect and are then absorbed for the nitrogen they contain. 
The Spanish moss has leaves covered with fine scales, which 
absorb water from the air. The flowers of this group are 
often brilliantly colored and the bracts that subtend them 
frequently take part in the color scheme. The flowers secrete 
nectar about the ovary and appear to be cross-pollinated. 
The seeds are in many instances provided with a feathery 
pappus, which enables them to travel about in the air until a 
favorable site on the branch of a tree is found. 
The spiderworts are more abundant in our region, but 
still are a mere handful compared with the more than three 
hundred species in warmer regions. Most of the species are 
noted for the short duration of the flowers, which, however, 
are brilliantly colored, and probably remain open long 
enough to entertain the pollinating insects. There is some 
evidence to prove that some of the flowers are capable of self- 
pollination. In an Old World species {Commelina Ben- 
ghalensis) cleistogamous flowers are produced from the 
rhizome. 
The pickerel weeds form a small family of less tiian 
twenty-five species, four of which belong to our part of tfie 
world. The common pickerel weed {Pontederia cordata) is 
famous for having three forms of flowers — with long, short 
