The Wild Hop may not unfrequently be seen in the copse and hedgerow, especially in the South of England. It has a thick branching perennial rootstock—in the cultivated plant called a “set”—from which are produced several long, thin, but tough twining stems that turn with the sun, and tightly clasp the nearest small tree or shrub. It has no tendrils like the vine, but climbs like the convolvulus by simply twining with the sun as it grows. Its lobed and coarsely toothed leaves are very similar to those of the grape-vine, but very rough. The leaves are in pairs, and at the base of the leaf-stalk is a pair of long curved stipules. The Hop is what botanists term a diœcious plant, because staminate flowers only are produced by one individual, and pistillate only by another, making cross-fertilization imperative. It is not the insects, however, that effect this crossing in the Hop, but the wind. The flowers are all small; the staminate produced from the axils of the leaves in long drooping panicles. They have no petals, but there are five sepals and five anthers attached to their bases. Each pistillate flower has a membranous sepal, an ovary, and two long tapering purple stigmas. Two of these pistillate flowers are produced in the axil of a green, broad, concave bract or scale. A number of these twin-flowered bracts are united into a dense spike, and after fertilization this develops into a large cone-like head of yellow scales with resinous glands at their base, which yield a resinous substance called lupuline. The true fruit is a little nut, which is enclosed in the sepal under the bracts. It flowers in July and August. It is the only British species. Beside their extensive use in brewing, the flowers are frequently used to stuff pillows, their narcotic odour inducing sleep.
The Salad Burnet (Poterium sanguisorba).
When “cool tankards” were more generally compounded than they are to-day, Salad Burnet was a better-known plant, for, like Borage, it formed one of the ingredients. It was used also in the salad bowl, its leaves having a flavour very similar to that of cucumber. It is a perennial, the rosette of radical leaves springing from a stout rootstock. The leaves are all pinnate; the leaflets in pairs, coarsely toothed, and a terminal leaflet. The stems are slender, branched, and the flowers are gathered into a purplish head. They have no petals, and are of two kinds: the upper ones have a four-lobed calyx with a narrow mouth, from which two styles with brush-like stigmas are exserted; the lower bear both stamens and stigmas, or stamens only. The stamens are four in number, attached to the mouth of the calyx, and the anthers hang out. The plant may be found abundantly in dry pastures, especially in a chalk district, flowering from June till August.
The Rough Burnet (P. muricatum), found in cultivated fields in the Midlands and South of England, is probably only a variety of sanguisorba, owing its large size and roughness to the richer soil it finds in the fields.
The Great Burnet (P. officinale), was formerly regarded as constituting a separate genus, Sanguisorba, but it is very similar to the Salad Burnet. Its flowers, however, are all alike, and contain both stamens and pistils. It is much larger than Salad Burnet, and its flower-heads more cylindric, longer, and of a darker purple hue. The stamens, too, instead of hanging far outside the calyx, are no longer than the lobes of that organ. The flowers produce honey, and are fertilized by insects. The leaflets are fewer and longer in this species. Its habitat is damp meadows, and its flowering time the same as Salad Burnet.
The name Poterium is the Latin term for a drinking-cup, in allusion to its use indicated above.
Salad Burnet.
Poterium sanguisorba.
—Rosaceæ.—
Ivy.
Hedera helix.
—Araliaceæ.—