Chapter II: Botany

The genus Asparagus belongs to the Lily Family. It comprises about one hundred and fifty species, and these are spread through the temperate and tropical regions of the Old World. One-half of these species are indigenous to South Africa, and it is from this region that the most ornamental of the greenhouse species have been obtained.

All the species are perennial, with generally fleshy roots or tubers. The stems are annual in some, perennial in others, most of them being spiny, climbing shrubs, growing to a length of from five to twenty or even fifty feet. The true leaves are usually changed into spines, which are situated at the base of the branches and are often stout and woody. The false leaves, termed cladodia, are the linear or hair-like organs which are popularly called leaves; they are in reality modified branches. These cladodia are nearly always arranged in clusters at intervals along the branches, and the flowers generally spring from their axils. They usually fall off the hardy species in winter, and they are easily affected by unfavorable conditions in all the species. Most of them flower and fruit freely under cultivation, so that seeds are available for propagation.

ORNAMENTAL SPECIES

_A. medeoloides_ (_Myrsiphyllum asparagoides_), popularly known as Smilax.--For many years this has been, and is yet, one of the most commonly grown and the most serviceable of the plants used by florists as "green." It is readily grown from seed in the greenhouse. While a few other species of asparagus have been close rivals, it is yet unexcelled for many purposes of floral decorations.

_A. plumosus_ (the plumy asparagus).--A very graceful climbing plant which for finer decoration has largely taken the place of smilax, its foliage being finer than that of the most delicate ferns, and will last for weeks after being cut. The whole plant is of a bright, cheerful green. Its branches spread horizontally, and branch again in such a manner as to form a flat, frond-like arrangement, the leaves being very numerous, in clusters of about a dozen, bright green, and one-half inch long. A native of South Africa, where it climbs over bushes and branches in moist situations. There are several named varieties of this, most of which have originated in gardens. The most distinct are _A. tenuissimus_ and _A. plumosus nanus_, the fern-like appearance of which is seen in Fig. 2.

_A. Sprengeri._--This is one of the best and most attractive house plants of recent introduction. It is of graceful form and habit when grown as a pot plant, but it is equally well suited for planting in hanging baskets. Its fronds are frequently four feet long, of a rich shade of green, and very useful for cutting, retaining their freshness for weeks after being cut. As a house plant it has exceeded expectations, as it stands dry atmosphere better than the older kinds of ornamental asparagus, and is not particular as to any special position. It delights in a well-enriched soil, rather light in composition, with plenty of drainage, and grows very rapidly. It is decidedly pretty when in bloom, its little flowers being pure white on short racemes, and the anthers are of a bright orange color. Fig. 3 gives a good idea of its graceful habit.

_A. falcatus._--One of the most striking twining plants for a large, temperate house. At the Kew Gardens, in London, England, is an enormous specimen of this species which is trained against the northern staircase, where it has formed a perfect thicket two yards through and twenty-five feet high, of long, rope-like, intertwining, spinous, fawn-colored stems, some of them fully fifty feet long, and clothed with wiry, woody branches, bearing whorls of leaves from two to three inches long and nearly one-fourth of an inch wide, falcate and bright green. The young stems are thick and succulent and gray-green, mottled with brown. For large conservatories, and particularly in moist, shady corners, where ordinary climbers will not thrive, this is an ideal plant. It is a native of the tropics of Asia and Africa, as well as the Cape.

_A. laricinus_ (Fig. 4).--This handsome species has been in the Kew collection at least twenty years. It is grown in the succulent house, where, from a vigorous root system, it sends up annual stout succulent shoots, which grow to a length of about twelve feet, and when fully developed are decidedly ornamental. The stems are perennial, terete, dark brown, woody, one-half inch in diameter at the base, very spinous, freely branched, and branches zigzag and gray, the leaves in clusters one-fourth inch apart, hair-like, one and one-half inches long, bright green, persistent. Flowers axillary, many in a cluster, small, campanulate, white. Berries globose, dull red, one seeded, one-sixth of an inch in diameter. Common in various parts of South Africa. It is an excellent pillar plant.

_A. racemosus._--This species is spread throughout the tropics of Africa and Asia; the Cape form of it is represented at Kew under the name of variety _tetragonus_, as shown in Fig. 5. This is a vigorous grower, with woody stems nine feet long, prickly at the base, fawn colored, freely branching above, each branch having at its base a sharp spine three-quarters of an inch long. The leaves are of a gray-green hue, four-angled, one-quarter of an inch long. Flowers in racemes two inches long, whitish, very fragrant. Berry red, globose, pulpy, one-seeded. An excellent climber for rafters, pillars, etc., growing vigorously under ordinary treatment. Its root system is a dense mass of tubers.

_A. sarmentosus_ (Fig. 6).--An elegant evergreen species from South Africa, where it grows freely in moist situations, forming dense, brushy stems with short prickles, and studded with white, starry, fragrant flowers, which are followed with bright scarlet, pea-like berries; has stems four feet high, freely branched and clothed with dark green flat leaves three inches long. It is also grown in pots and baskets for the Cape-house, and when in flower it is greatly admired.

_A. Broussoneti._--A beautiful hardy perennial climber from the Canary Islands, growing ten feet high; feathery foliage and scarlet berries. In the autumn this is very ornamental.

Among the most noteworthy of other ornamental species are: _A. Aethiopicus_, _Africanus_, _Asiaticus_, _Cooperi_, _crispus_, _declinatus_, _decumbens_, _lucidus_, _retrofractus_, _scandens_, _tenuifolius_, _trichophyllus_, _umbellatus_, _verticillatus_, _virgatus_, etc., etc.

EDIBLE SPECIES

_Asparagus officinalis._--While the young sprouts of a few other species may be used as food, this is the only one which has found a permanent place in cultivation. It is a branching, herbaceous plant, reaching a hight of from three to seven feet; the filiform branchlets, three to seven inches long, less than one-quarter inch thick, are mostly clustered in the axils of minute scales. The rootstock, or "crown," is perennial, and makes a new growth each year of from one to three inches, extending horizontally, and generally in a straight line. It may propagate from both ends, or from only one, but in either case the older part of root stalk becomes unproductive and finally dies. Fig. 7 shows the new portion of the rootstock crowned with buds for the production of new shoots, while the older portion bears the scars and dead scales of previous growths. From the sides and the lower part of the rootstock numerous cylindrical, fleshy roots start and extend several feet horizontally, but do not penetrate the soil deeply. In the course of time the older roots become hollow and inactive without becoming detached from the rootstock. The young root formation always takes place a little above the old roots, which circumstance explains why the asparagus plants gradually rise above the original level, thus necessitating the annual hilling up or the covering of the crowns with additional soil.

The asparagus flowers are mostly solitary at the nodes, of greenish-yellow color, drooping or filiform, jointed peduncles; perianth, six-parted, campanulate, as seen in Fig. 8. Anthers, introrse; style, short; stigma, three-lobed; berry, red, spherical, three-celled; cells, two-seeded. While the flowers are generally dioecious--staminate and pistillate flowers being borne on different plants--there appear also hermaphrodite flowers, having both pistils and fully developed stamens in the same flower. Fig. 9 shows a pistillate, Fig. 10 a staminate, and Fig. 11 a hermaphrodite or bisexual flower.

In one case, at least, the author has also observed that a plant which has been barren of seed at first changed into a seed-bearing plant the following year. Similar changes in the sexuality of strawberries have been observed under certain conditions. These facts may explain, in a measure, the difficulty experienced in raising permanently sterile asparagus plants.

_Asparagus acutifolius._--A native of Southern Europe and Northern Africa. It has a fleshy rootstock, hard, wiry, brown stems, five to seven feet high, with rigid branches three to six inches long, thickly closed, with tufts of gray-green, hair-like, rigid leaves, which in exposed situations are almost spinous. Flowers yellow, a quarter of an inch in diameter, fragrant. The young sprouts are tender, and, when cooked, of a peculiar aromatic flavor. In their native home they are used like the cultivated kind.

_A. aphyllus._--Indigenous to Greece, where the young shoots are commonly used as food, especially during Lent.