163 
ON PLANTS IN RELATION TO ANIMALS. 
By Professor James Buckman, F.G.S., F.L.S., &c. 
(Continued from p. 97.) 
The next family of plants to occupy our attention will be 
that to which the name of Crucifera has been given. 
The Crucifera or cross-bearing order of plants is readily 
distinguished from all others by the peculiar arrangement of 
its floral envelopes united with a form of stamens which 
would appear to be confined to it. 
Thus the sepals consist of four distinct leaves and alter¬ 
nating with these are four distinct petals arranged cross¬ 
wise. The stamens are four longer and two shorter ones 
= 6 . 
According to Bentham* the “ Crucifer Family ” consists 
of herbs, or rarely undershrubs, with alternate leaves and 
no stipules ; the flowers in terminal racemes, which are 
generally very short or reduced to a corymb when the flow¬ 
ering commences, but lengthen out as it advances. Sepals 
4, petals 4, equal, or two on the outer side larger. Stamens 
6, of which two are generally shorter or rarely deficient. 
Ovary solitary two-celled. Style single, often very short or 
almost none, with a thin partition, from which the valves 
generally separate at maturity; or, in a few genera, the pod 
is one-celled or indehiscent, or separates transversely into 
several joints. Seeds without albumen attached, in each 
cell, alternately, to the right and left edges of the partition. 
An extensive and very natural family, widely spread over 
the globe, but chiefly in the northern hemisphere ; scarce 
within the tropics, and in some districts entirely unknown. 
The number of sepals, petals, and stamens readily distinguish 
Crucifers from all other British plants, but the discrimination 
of the numerous genera into which they are distributed is a 
much more difficult task. 
The characters are necessarily derived chiefly from the 
pod and the seed, and are often very minute. It is therefore 
absolutely necessary, in order to name a crucifer to have the 
specimen in fruit, and to examine the seed it must be ripe ; 
it should then be soaked and the outer coating carefully 
taken off, in order to lay bare the embryo, and observe the 
position of the radicle on the cotyledons, which is now con¬ 
sidered as the most essential among the generic characters. 
* See ‘ Illustrated Handbook of the British Flora,’ vol. i, p. 38. 
