Part 10

PAPILIONACEAE. Pea Family proper.

Herbs, shrubs, or trees. Leaves.--Usually alternate; compound; with stipules; the latter sometimes transformed into thorns or tendrils. Flowers.--Seldom solitary; usually in spikes, racemes or umbels. Calyx.--Five-toothed; often bilabiate. Corolla.--Irregular; of five petals; papilionaceous--i.e. the two lower petals more or less coherent, forming the keel; the two lateral ones often adherent to the keel, called the wings; the upper petal called the standard or banner. Stamens and pistil inclosed in the keel. Stamens.--Ten; their filaments either coherent into a tube surrounding the pistil; or nine of them united into a sheath, open above, the tenth lying in front of the cleft; or rarely all distinct. Ovary.--Superior; one-celled. Style.--Simple and incurved. Stigma.--Simple. Fruit.--A two-valved pod, of which the garden pea is typical.

The Pea family, including its three sub-orders, is one of the most important plant-families known. It is distributed over almost the entire world, and furnishes some of the most valuable products to man. The Judas-tree, the numerous acacias, and the sweet pea, are well known in our gardens; while among our most valuable vegetables are the bean, the pea, and the lentil. The clover and alfalfa are extremely important forage plants.

The order furnishes several important timber-trees, in different parts of the world, such as the Rosewood, the Laburnum, and the Locust; and yields numerous products of economic importance, such as licorice, senna, gum Senegal, gum Arabic, gum tragacanth, balsam of copaiba, balsam of Tolu, indigo, logwood, red sandalwood, etc.

=Compositae.= Composite Family.

Herbs, rarely shrubs. Leaves.--Usually alternate; without stipules. Flowers.--In a close head on a common receptacle, surrounded by an involucre, whose divisions are called scales or bracts. Calyx-tube.--Adnate to the one-celled ovary; its limb (called a pappus) crowning its summit in the form of bristles, awns, scales, teeth, etc.; or cup-shaped; or else entirely absent. Corolla.--Either strap-shaped or tubular; in the latter chiefly five-lobed. Stamens.--Five (rarely four); on the corolla; their anthers united in a tube. Style.--Two-cleft at the apex. Fruit.--An akene. Flowers with strap-shaped corollas are called ray flowers or rays. The tubular flowers compose the disk.

The Composite family is the largest of all plant-families, numbering twelve thousand species and upward, and is widely distributed over the world. In the cooler parts of the world the plants are mostly herbaceous, but toward the tropics they gradually become shrubs, and even trees. In North America they comprise about one sixth of all the flowering plants.

For so large a family there are comparatively few useful plants found in it. Among the products of the order, may be mentioned chicory, lettuce, the artichoke, the vegetable oyster, arnica, chamomile-flowers, wormwood, absinth, elecampane, coltsfoot, taraxacum, oil of tansy, etc. But our gardens owe to this family innumerable beautiful and showy plants such as the China aster, the chrysanthemum, the cosmos, zinnia, dahlia, ageratum, gaillardia, coreopsis, sunflower, etc., etc.

The plants of this family are quickly recognized by the flowers being always borne in a head and surrounded by an involucre, and presenting the appearance of a single flower. The heads are sometimes made up entirely of one kind of flower. The dandelion and the chicory are examples of a head made up entirely of ray-flowers, while the thistle consists of tubular flowers only. The more common arrangement, however, is the mixed one, comprising both tubular disk-flowers and strap-shaped rays, as in the daisy. The seeds are usually furnished with silken down or a delicate parachute to waft them abroad.

The identification of the flowers of this order is a very difficult matter, even for experienced botanists.

=Labiatae.= Mint Family.

Herbs with square stems. Leaves.--Opposite; usually aromatic. Flowers.--Axillary, or often in whorls or heads. Corolla.--Bilabiate (rarely regular). Stamens.--Four (or only two). Ovary.--Deeply four-lobed; becoming four seedlike nutlets. Style single; arising from the midst of the lobes.

The plants of this order are easily recognized by the traits in the above description. But some of these traits are shared by the plants of the Figwort family, which have also the bilabiate corolla. The distinguishing character, however, is always to be found in the four-lobed ovary for the Figworts have a two-celled ovary.

This order is a large one; and there are no noxious or poisonous plants to be found in it. On the contrary, it comprises many useful plants, too well known almost to need enumeration--such as the lavender, peppermint, sage, horehound, thyme, spearmint, horsemint, pennyroyal, etc.

GENERA

CEANOTHUS, L. Buckthorn Family.

Shrubs or small trees, sometimes spinescent. Leaves.--Opposite or alternate; petioled; variously toothed or entire. Flowers.--Blue or white; small, usually not more than two or three lines across; borne in showy thyrsoid or cymose clusters. Calyx.--Petaloid; with short tube and five-cleft border, the lobes acute and connivent. Petals.--Five; long-clawed; hooded; inserted on the calyx-tube. Stamens.--Five; opposite the petals; long exserted. Ovary.--Three-lobed; three-celled. Style short; three-cleft. Fruit.--Dry; consisting of three dehiscent nutlets; sometimes crested.

The genus Ceanothus is mainly a Western one. Of its thirty or more species, two thirds are found in the region between the Rocky Mountains and the Pacific Ocean.

In California we have about twenty species; and these all hybridize to such an extent, that often the determination of any given species is a very difficult matter. The genus reaches its culmination in the mountains of Santa Cruz County, where there are many beautiful species. Many of the species are commonly known as "California lilac."

LUPINUS, Catullus. Pea Family.

Leaves.--Palmately divided, with from one to sixteen leaflets; stipules adnate; seldom conspicuous. Leaflets.--Entire; sessile. Flowers.--In terminal racemes, whorled or scattered. Calyx.--Deeply bilabiate; upper lip notched; lower usually entire, or occasionally three-toothed or cleft. Corolla.--Papilionaceous. Standard.--Broad, with sides reflexed. Wings.--Falcate; oblong; commonly slightly united at the tip in front of and inclosing the falcate, usually slender, pointed keel. Stamens.--With their filaments united in a tube; of two forms; five with longer and basifixed anthers; the alternate five with shorter and versatile ones. Pod.--Compressed; straight; two-valved. Style slender. Stigma bearded.

The Lupines are mostly plants of Western America. In fact, they are so abundant between the Rocky Mountains and the Pacific Ocean that that territory is known among botanists as the "Lupine Region."

The species, which are very numerous, are difficult of determination, requiring very long technical descriptions, which cannot be given in a work like the present. For this reason we have been able to give but a few of the more easily recognized.

We have in California upwards of forty species. They are of little economic importance, although one or two species have been found very useful in the reclaiming of sand-dunes. Several species have been cultivated for ornament. The leaves are often beautiful and the flower-clusters showy.

The generic name is supposed to come from the Latin lupinus, a wolf, and to have been given because of the voracity evinced by the species in exhausting the soil.

ASTRAGALUS, Tourn. Pea Family.

Herbs, or sometimes plants woody at base. Leaves.--Alternate; with stipules; unequally pinnate. Flowers.--Rather small; chiefly in simple axillary spikes or racemes, upon a commonly elongated peduncle; papilionaceous. Calyx.--Five-toothed. Corolla and its slender-clawed petals usually narrow. Keel not pointed. Stamens.--Nine united; one free. Ovary.--One-celled; sometimes apparently two-celled. Pod.--Very various; commonly inflated. Seeds.--Few to many on slender stalks; generally small for the size of the pod.

The genus Astragalus is a very large one, comprising many species in most parts of the world, save Australia and South Africa. About two hundred species are native of North America, most of which are found in the region west of the Mississippi River. Of these several are known as "loco-weed," and are poisonous to sheep and cattle.