HOPS. Humulus Lupulus, Linn. Urlicarecc. Figs. 572-576.
By Jared Van Wagenen, Jr.
A perennial twining herb produ cing burs or "hops" that are used in the making of beer. It has long shoots often reaching twenty-five to thirty feet in a season; rough hairy, the stems having minute prickles pointing downward ; leaves ovate or orbicular-ovate in general outline, deeply three-lobed (sometimes five to seven-lobed). or the upper ones not lobed ; mar gins strongly and uniformly dentate ; petioles long; staminate flowers in panicles two to six inches long ; hops (mature pistillate catkins) oblong or ovoid, loose and papery, straw-yellow, often two inches or more long, glandular and odoriferous.
The hop has a tough, fibrous inner bark and a color less juice which makes an indelible stain on white fabrics. The stems climb as much as thirty feet high by the beginning of the flowering period, lengthen ing from a well-marked terminal "head," and nor mally twining by rotating spirally around their sup ports, "clock-wise" or "fol lowing the sun." The hop is dicecious, i. e., the pistil ]ate and staminate flowers are borne on separate plants. The fruit may be regarded as a compact cat kin, largely made up of the axis together with the large foliaceous bracts, each of which is covered at its base by a yellow, granular, resin-like mate rial called lupulin. This is the essential principle in the hop, and imparts the bitter taste to beer. There are also a few seeds, although seed-production is irregular and scanty, a large proportion of the fer tile flowers failing to mature seed. The plant is unusually drought-resistant and grows most rapidly in extremely hot weather, sometimes increasing in length as much as a foot a day. The stems cling closely to a pole or string and, when once well started, will follow it with very little trouble. The growth is almost wholly increase in length until the beginning of the flowering period (mid-July in New York), after which short compound lateral branches are thrown out from the axils of the leaves, on which the flowers appear and the plant ceases to "run." Botanically, the hop is closely
related to hemp and is included in the great nettle family.
Geographical distribution.
There are few plants that are more widely grown than the hop. It is native in Europe and is reported from practically every European country and from Canada, Australia, New Zealand, Tas mania and other countries. In the United States, where it has been an important crop in certain sections for at least a century, its commercial pro duction is limited to four states, in the order named: Oregon, California, New York and Washington, although at times it has been grown in Wisconsin, Michigan and Vermont. The relative importance of the crop in New York seems to be on the decline while it is increasing in the West, owing to the better climatic conditions and cheaper methods of production. The wild form of the plant, which dif fers considerably from the cultivated hop, although easily recognizable, is found along certain alluvial creek-bottoms of the northeastern United States.
The United States Department of Agriculture makes no official estimate of production, but by the best obtainable statistics, in the five years ending with 1905, the total production of the United States has ranged between 39,000,000 and 51,000,000 pounds. In the same series of years about 20 per cent of the crop has been exported. The United States returns less than one-fifth of the world's total production.
Culture.
Soils.—The hop seems to adapt itself readily to a wide variety of soils, provided only that they are well drained. In parts of the East it is grown extensively on rich alluvial creek-bottoms and on poor sandstone hills. A rich sandy loam that is moist, but not wet, is preferable. The commercial value of the cured hop depends very largely on its color, a bright straw-color being the ideal, and this will not be secured on soils in which nitrogen is too abundant. A slight elevation, protected from north and northwest winds, and sloping toward the east or southeast, is preferable.