Such stems are called rootstocks.

A thick, short rootstock provided with buds, like the potato, is called a tuber.

Asplenium Ruta-muraria Rootstock of Lady Fern (Two parts) Sori of Lady Fern.

The young ferns should be transplanted in early spring with as much of the long, running rootstock as possible.

The term maidenhair may have been suggested by the black, wiry roots growing from the slender rootstock, or by the dark, polished stems, or, as Clute explains it, "because the black roots, like hair, were supposed, according to the 'doctrine of signatures' to be good for falling hair, and the plant was actually used in the 'syrup of capillaire'[A] (Am. Botanist, November, 1921).

The sterile fronds resemble those of the cinnamon fern, but the latter grow in crowns, with a single frond in the center, while the fronds of the chain fern rise singly from the creeping rootstock, which sends them up at intervals all summer.

ATHÝRIUM ANGÚSTUM Asplènium Fìlix-femina The rootstock or rhizome of the Upland Lady Fern here pictured shows how the thick, fleshy bases of the old fronds conceal the rootstock itself.

ATHÝRIUM ANGÚSTUM Asplènium Fìlix-femina The rootstock or rhizome of the Upland Lady Fern here pictured shows how the thick, fleshy bases of the old fronds conceal the rootstock itself.

In the Lowland Lady Fern the rootstock is but slightly concealed by old stipe bases, and so may be distinguished from its sister fern.

[Illustration: Rootstock of the Upland Lady Fern]

Stipe continuous with the rootstock.

Rootstock slender and creeping from which fronds are produced all summer, in appearance like the small, ternate divisions of the bracken.

The heavy rootstock rises slightly above the ground and is clothed at the crown with shaggy, brown scales.

Nephròdium Fìlix-mas Fronds lanceolate, pinnate, one to three feet high growing in a crown from a shaggy rootstock.

Its rootstock produces the well-known fìlix-mas of the pharmacist.

Stipes jointed an inch or so above the rootstock.

The rusty Woodsia is decidedly a rock-loving fern, and often grows on high cliffs exposed to the sun; its rootstock and fronds are covered with silver-white, hair-like scales, especially underneath.

As the short stipes separate at the joints from the rootstock, they leave at the base a thick stubble, which serves to identify the fern.

As the name implies, the plant is smooth, except for the chaffy scales at or near the rootstock, which mark all the Woodsias, and many other ferns, and which serve as a protective covering against sudden changes in extremes of heat and cold.

The sensitive fern has a running rootstock, scattered fronds, and netted veins; while the ostrich fern has an upright rootstock, fronds in crowns, and free veins.

The sensitive fern has a running rootstock, scattered fronds, and netted veins; while the ostrich fern has an upright rootstock, fronds in crowns, and free veins.

Onoclèa sensíbilis Fronds one to three feet high, scattered along a creeping rootstock, broadly triangular, deeply pinnatifid, with segments sinuately lobed or nearly entire.

Ophioglóssum vulgàtum Rootstock erect, fleshy.

Lance-leaved Grape Fern. GRAPE FERNS Botrýchium Rootstock very short, erect with clustered fleshy roots; the base of the sheathed stalk containing the bud for the next year's frond.

OBLÌQUUM Rootstock short, its base including the buds of succeeding years.