Part 9

THE STAMEN

The =stamen= consists of two parts--the =filament= and the =anther=. The filament is the stalk of the stamen. The anther is the little case holding the =pollen=, or powdery substance, which, falling upon the stigma, is conducted downward into the ovary, where it quickens the ovules into life. The anther normally consists of two cells, which more often open lengthwise for the discharge of the pollen, though they sometimes open by terminal pores or chinks, or by uplifting lids.

Stamens sometimes undergo a morphological change, taking the form of scales or other bodies (as is the case in many of our Brodiaeas), when they are called =staminodia=.

THE PISTIL

The =pistil= is the organ occupying the center of the flower. It consists of three parts--the =ovary=, or the enlarged part below, consisting of one or more cells or cavities, and containing the ovules, or unfertilized seed; the =style=, or the stem which upholds the stigma; the =stigma=, or the roughened portion which receives the pollen.

The pistil is simple, when it has but one ovary, style, stigma, etc.; compound, if any one of these is duplicated.

THE FRUIT

The =fruit= is the ripened ovary. After the ovules have been fertilized, the ovary is called a =pericarp=. Fruits may be either fleshy or dry.

The following are some of the principal kinds of dry fruits:--

A =capsule= is a dry, dehiscent (splitting) fruit, composed of more than one carpel or division;

an =akene= is a small, dry, hard, one-celled, one-seeded indehiscent fruit;

a =follicle= is a pod formed from a single pistil, dehiscing along the ventral suture only;

a =legume= is a simple pericarp, opening by both seams.

a =samara= is a dry, indehiscent fruit, having a wing.

The following are some of the principal kinds of fleshy fruits:--

A =pome= is a fruit like an apple or pear;

the =pepo=, or =gourd=, fruit is like that of the melon, squash, etc.;

the =drupe= is like that of the cherry, plum, and peach;

the =berry= is like that of the grape, currant, and tomato.

=Aggregate fruits= are those in which a cluster of carpels, all of one flower, are crowded upon the receptacle into one mass; as in the raspberry and blackberry.

IMPORTANT PLANT FAMILIES AND GENERA

FAMILIES

=Cruciferae.= Mustard Family.

Herbs with pungent, watery juice. Leaves.--Alternate; without stipules; entire or divided. Flowers.--Generally in racemes. Sepals.--Four. Petals.--Four; usually with narrowed base or claw; the blades spreading to form a cross. Stamens.--Six; two of them shorter than the other four. Ovary.--Two-celled; rarely one-celled. Style undivided, or none. Stigma entire or two-lobed. Fruit.--A silique--i.e. a capsule, in which the walls separate upward away from a central partition.

The Mustard family is a very large one, comprising over a hundred and seventy genera, and containing between one and two thousand species. It is widely distributed over all parts of the world, but is most abundantly represented in the cooler or temperate regions. It furnishes us with many useful plants; such as the mustard, horseradish, radish, cabbage, turnip, cauliflower, etc.

The genera of this order are very closely allied, and very difficult of discrimination. The fruit, as well as the flower, is necessary in the study of any given species.

=Leguminosae.= Pea Family.

The order Leguminosae is divided into three well-marked sub-orders--the Pea family proper, the Brasiletto family, and the Mimosa family. But as all our genera, save Cercis, fall under the first, we shall describe that only.