THE 
AMERICAN NATURALIST. 
VoL: x. — JANUARY, 1876. — No. 1. 
BURS IN THE BORAGE FAMILY. 
BY PROFESSOR ASA GRAY. 
BUR in the light of morphological botany may be seen to be 
a seed, a fruit or a portion of one, a calyx, an involucre, or 
what not. Under the teleological aspect, which was once thought 
to be expelled from natural history, but which has come back in 
full force, a bur is one adaptation for the dissemination of seeds 
by cattle or other animals. 
One of the most familiar burs is that of the common hound’s- 
tongue (Cynoglossum), of the Borage family ; and those of one or 
two species of stickseed (of the nearly related genus Echinosper- 
mum) are equally troublesome, clinging as they do to the fleece 
or hairy coat of domestic animals and to clothing. These burs, 
morphologically, are not seeds, but quarter portions of seed-like 
fruits. They adhere for transport by means of prickles or pro- 
jecting points, which are either barbed or hooked at the tip; the 
grappling organs in some cases occupying the whole surface of 
the pericarp, in others particular portions of it. 
It is rather interesting to notice how in the same family, that 
is, among plants all constructed on the same particular plan, this 
same purpose is effected or attempted in different ways, and, as 
we may say, more or less successfully. The occasion of these re- 
marks came to me with a new plant of this order in which the bur 
proved to be formed of different materials from the ordinary burs 
of the family. 
It is worth noticing, moreover, that in what botanists must con- 
sider one and the same genus, and, so to speak, of one blood, the 
grappling organs may be either more or less developed, or rudi- 
mentary, or even wanting altogether, or when wanting to the 
seed-like fruits, may be developed on some neighboring part. - 
Copyright, A. S. PACKARD, Jr. 1875. 
