{Prickly ash} (Bot.), a prickly shrub ({Xanthoxylum
Americanum}) with yellowish flowers appearing with the
leaves. All parts of the plant are pungent and aromatic.
The southern species is {X. Carolinianum}. --Gray.
{Prickly heat} (Med.), a noncontagious cutaneous eruption of
red pimples, attended with intense itching and tingling of
the parts affected. It is due to inflammation of the sweat
glands, and is often brought on by overheating the skin in
hot weather.
{Prickly pear} (Bot.), a name given to several plants of the
cactaceous genus {Opuntia}, American plants consisting of
fleshy, leafless, usually flattened, and often prickly
joints inserted upon each other. The sessile flowers have
many petals and numerous stamens. The edible fruit is a
large pear-shaped berry containing many flattish seeds.
The common species of the Northern Atlantic States is
{Opuntia vulgaris}. In the South and West are many others,
and in tropical America more than a hundred more. {O.
vulgaris}, {O. Ficus-Indica}, and {O. Tuna} are abundantly
introduced in the Mediterranean region, and {O. Dillenii}
has become common in India.
{Prickly pole} (Bot.), a West Indian palm ({Bactris
Plumierana}), the slender trunk of which bears many rings
of long black prickles.
{Prickly withe} (Bot.), a West Indian cactaceous plant
({Cereus triangularis}) having prickly, slender, climbing,
triangular stems.
{Prickly rat} (Zo["o]l.), any one of several species of South
American burrowing rodents belonging to {Ctenomys} and
allied genera. The hair is usually intermingled with sharp
spines.