Humulus lupulus L. is a perennial herbaceous vine with horizontal and vertical roots. The horizontal roots spread out at depth of 20 to 30 cm and give rise to fibrous roots in the upper layers of soil. The vertical roots develop downward to a depth of 152 cm with a spread of 183 to 244 cm and no fibrous roots.
The stems are annual, slender, climbing, up to 9 m in length, often with stout hooked hairs. The leaves are opposite, cordate, 3 to 5 lobed, margins serrate, petioles slightly fleshy with stout hooked hairs.
The plants are dioecious with unisexual flowers on separate plants, but occasionally monoecious plants occur, in which case male or female flowers are often infertile. Humulus lupulus L. is wind-pollinated. The female inflorescence are cone-like, 2.5 to 5 cm long and the male flowers form in long racemes.
Distribution & Ecology
The plants are native to Europe and western Asia and currently cultivated in North and South America, Africa, Asia and Australia and have become naturalized in many areas. Hops are quite hardy if other growing conditions are good and can live for 10-20 years. When dormant, they withstand freezing, however, a severe frost will kill young, tender vines in spring.
Hops range from Boreal Wet through Subtropical Dry Forest Life Zones and are reported to tolerate annual precipitation of 3.1 to 13.7 cm (mean of 34 cases = 7.4) and annual temperature of 5.6 to 21.3 degrees C. They are suitable for temperate climates between latitudes 35 to 51N and 34 to 43S, with mean summer temperatures of 16 to 18 degrees C.
Images reproduced from the pamphlet:
Scot, Reginald, 1538?-1599.
A Perfite Platforme of a Hoppe Garden : and necessarie instructions for the making and mayntenaunce thereof, with notes and rules for reformation of all abuses, commonly practised therein, very necessarie and expedient for all men to haue, which in any wise haue to doe with hops.
Imprinted at London : By Henrie Denham, dwelling in Pater noster Rovve, at the signe of the Starre, 1576.
Houghton Library STC 21867 [1578 edition]
Bickerdyke, John, 1858-1933.
The curiosities of ale & beer : an entertaining history
London : Spring Books, 1965.
Botany Economic Botany TP577 .B35x 1965