=Cactus=, _n._ From a Greek word meaning “a prickly plant”; a group of
plants which usually grow in dry places and have prickles or thorns
instead of leaves. The prickly pear grows wild in northern
latitudes, and others, such as the night-blooming cereus, are often
seen in hothouses.
=Callous=, _a._ L. _callosus_, hard-skinned, thickened and hardened.
Applied to a hard place on the skin, usually the result of friction.
=Calyx=, _n._ From a Greek word meaning “to cover”; the outer set of
envelopes which form the perianth of a flower. If the perianth has
but one set of envelopes it is called the calyx.
=Capillary attraction=, _n._ The force which causes liquids to
disperse through fabrics or tissues. If one end of a towel be placed
in a bowl of water, the whole towel will be wet in course of time.
=Carbon=, _n._ L. _carbo_, a coal; a substance very widely distributed
and existing under various forms. Coal is one form of carbon,
graphite another, the diamond a third. One atom of carbon combined
with two of oxygen form carbon dioxide.
=Carbon dioxide=, _n._ A heavy gas, found as an impurity in the air.
It is breathed out by animals and plants, and absorbed and used as a
food by plants.
=Castor oil=, _n._ The oil obtained from the seeds of the castor-oil
plant. Used as a medicine and also in dyeing cotton certain colors.
=Cell=, _n._ L. _cella_, a small room; a case or cup in which
something is held, as anther cell, ovary cell, honeycomb cell; also
the protoplasmic particles of which plants and animals are built up.
=Candelabrum=, _n._ L. _candela_, a candle; a candle stick; any
branched candlestick. A candelabrum rests on a post, while a
chandelier is suspended. Candelabra is the plural.
=Chasm=, _n._ From a Greek word meaning “a yawning hollow”; a wide,
deep cleft.
=Chlorophyll=, _n._ From two Greek words meaning “light green” and
“leaf,” leaf-green; the green coloring matter of vegetation.
=Columbine=, _n._ L. _columba_, a dove; a flowering plant which gets
its name from the fancied resemblance of its petals and sepals to
the heads of doves round a dish.
=Complexity=, _n._ L. _com_, together, _plectere_, to weave; formed by
a combination of simple things.
=Convolvulaceæ=, _n._ The name of a family of plants to which belong
the morning-glory and bindweed.
=Cornucopia=, _n._ L. _cornu_, horn, _copia_, plenty; horn of plenty.
=Corolla=, _n._ L. _corolla_, a little crown; a garland; the floral
envelope within the calyx, very often bright colored.
=Cotton-seed oil=, _n._ An oil expressed from the seeds of the cotton
plant and, when purified, used instead of olive oil.
=Crete=, _n._ An island to the south of Greece.
=Crocus=, _n._ An early spring flower.
=Cross-fertilization=, _n._ The fertilization of the ovules of one
flower by the pollen of another.
=Cross-fertilized=, _a._ Fertilized by the pollen from another plant.