12 
PRINCIPIA 
2d. Siliqua (a pod) is a pericarpium of two valves; but 
as some are long, others round or broad, Linnaeus thought 
it necessary to distinguish them by their form, into siliqua 
and silicula ; which gives rise to the two orders in the class 
tetradynamia : The siliqua means a long pod, being much 
longer than broad, as in brassica, sinapis, &c.; the silicula 
(a little siliqua) is a roundish pod, either flat, or spherical, and 
the length and breadth nearly equal, as in iunaria, draba, 
thlaspi, &c. in both, the apex, which had been the style, is 
often so long beyond the valves, as to be of equal length with 
the pod ; and the seeds in both are fastened alternately by a 
slender thread, to both the sutures or joining of the valves, 
3d. Legumen (pulse) is also a pod, and is likewise a perb 
carpium of two valves, wherein the seeds are fastened to short 
receptacles along the upper suture' only, on each side alter¬ 
nate : This chiefly belongs to the papilinaceous (butterfly) 
flowers of the class diadelphia. 
4th. Folliculus (a little bag, in former editions called 
conceptaculum ) is a pericarpium of one valve only, opening 
lengthways on one side, and the seeds not fastened to the 
suture, but to a receptacle within the fruit, as in apocyuuni, 
asclepias, &c. 
5th. Drupa (from drupse, unripe olives) is a pericarpium 
that is generally succulent, or pulpy, having no valve or ex¬ 
ternal opening, and generally contains within its substance a 
stone or nut;* that is, a seed enclosed with an hard ligneous 
crust, as oka, cornus, juglans, primus, amygdalm, &c.; and 
when the drupa is seated below the calyx, it is furnished with 
an umbilicus, like the pomum. 
6th. Pomum (an apple) is also a pericarpium that is suc¬ 
culent or pulpy, and without valve; but containing in the 
middle a membranous capsule, with several cells or cavities. 
* All drupes have not a stone or nut (properly so called) for the seed, as in 
schrebera, &c. neither have all seeds that are called nuts a drupe for the peri¬ 
carpium, as lnfagus it is called a capsule, one-celled, four-valved, containing two 
nuts; in quercus, as also in corylus, and trap a, there is no pericarpium, the nuts 
are lodged in the calyx ; and in pinus the nut is lodged in the calyx strobile ; m 
cannabis the seed is also called a nut lodged in the calyx. See note to bacca. 
