flower previously visited, cross-pollination takes place. A single normal visit is sufficient to effect pollination, and all subsequent visits are useless. After the flowers have been exploded, or “tripped,” they continue to secrete nectar and receive insect visits. This is clearly an imperfection, since the visitors are no longer beneficial. Honeybees usually thrust their tongues sidewise between the petals, and gather the nectar without touching the anthers or stigma. The flowers are very frequently visited normally by leaf-cutting bees and bumblebees. For climatic reasons seed-growing is restricted chiefly to Utah, Kansas, Nebraska, California, Arizona, Colorado, Oklahoma, Idaho, Montana, and Wyoming, named in the order of yields. According to Alter, “The climate is the limiting factor in seed production generally, and current weather is the major control affecting any yield.” A humid climate is unfavorable to the production of seed. (Fig. 15.)

The common alfalfa is probably of Asiatic origin, as it has been found growing wild in Afghanistan, Persia, and the region south of the Caucasus. In China it has been under cultivation from a very early date. The plant was brought into Greece at the time of the Persian war, 470 B. C., from Media, whence the generic name Medicago. In Italy it has been cultivated from about the first century, and is well described by Virgil and Pliny. During the Middle Ages it received the vernacular name of lucerne, from the valley of Luzerne in Piedmont in Northern Italy. It was long popularly known under this name in Europe, outside of Spain, and in eastern North America.

It was also very early introduced into northern Africa, where it was called alfalfa, a word of Arabic origin signifying “the best fodder.” During the Moorish invasion it was carried into Spain, and later was brought by the Spaniards to Mexico and South America, and finally, in 1854, was carried from Chile to California. It was first heard of in England about 1650. Under the name of lucerne the early colonists introduced it into eastern North America, where it still grows spontaneously in fields and waste places; but the first attempts to cultivate it proved unsuccessful. Other common names are Spainsh trefoil, Burgundy, Brazilian, and Chilian clover. It is also known as purple Medick, from the color of the flowers and the Latin word Medica (Media), and snail clover from its twisted pods.

ALFALFA, WILD. — See Wild Alfalfa.

ALFILERILLA (Erodium cicutarium). — Also called pin-clover, stork’s-bill, heron’s-bill, and pin grass. Alfilerilla is derived from the Spainsh word for pin. The fruit slightly resembles a heron’s bill, whence the generic name Erodium, the Greek for heron. This valuable forage plant is cultivated in several western states, and as a weed is very abundant from Oregon to Texas. The pink flowers are a valuable source of honey, and also furnish much pollen. Nectar is secreted on the outer side on the base of each of the five outer stamens, and collects in a little hollow at the base of each sepal. Honeybees have been often seen gathering both pollen and nectar. Alfilerilla is readily eaten by stock, and compares well with red clover in nutritious value.

Also called filaria and filaree, contractions of the Spanish alfilerilla, a pin, so-called from the form of the carpels or seed pods.

The same English names are also applied to another species of Erodium (E. moschatum), which very closely resembles the preceding species, but differs from it in the broader segments of the leaves and the whiter stems. In California it is very abundant in the fertile lands of the valley orchards and vineyards, and in the northern Coast Ranges, where it forms extensive growths. It begins blooming in March and April. Musk clover.

ALGAROBA. — See Mesquite.

ALKALI-HEATH (Frankenia grandiflora). — A herbaceous or shrubby plant, common on the alkaline plains of the interior of California, which yields nectar in late summer and fall. The Yerba Reuma of the Spaniards.

ALMOND (Primus Amygdalus). — The conspicuous sessile flowers appear before the leaves. Large groves are valuable in spring both for nectar and pollen. The