The plants generally have a rhizome bearing radical leaves, as in asphodel, rarely a stem with a tuft of leaves as in Aloe, very rarely a tuber (Eriospermum) or bulb (Bowiea).
LICHEN (lichen Tuber), in medical terminology, a papular disease of the skin, consisting of an eruption in small thickly set, slightly elevated red points, more or less widely distributed over the body, and accompanied by slight febrile symptoms.
Metamorphosis.It has already been pointed out that each kind of member of the body may present a variety of forms. For example, a stem may be a tree-trunk, or a twining stem, or a tendril, or a thorn, or a creeping rhizome, or a tuber; a leaf may be a green foliage-leaf, or a scale protecting a bud, or a tendril, or a pitcher, or a floral leaf, either sepal, petal, stamen or carpel (sporophyll); a root may be a fibrous root, or a swollen tap-root like that of the beet or the turnip. All these various forms are organs discharging some special function, and are examples of what Wolff called modification, and Goethe metamorphosis.
Behind the transverse fissure the lower end of the Spigelian lobe is seen as a knob called the tuber papillare, and from tree right of this a narrow bridge runs forward and to the right to join the Spigelian lobe to the right Vena cava in its fossa lobe and to shut off the transverse fissure from that for the vena cava.
The tuber is a fleshy underground stem, furnished with eyes which are either visible, as in the potato and in some familiar kinds of Tropaeolum (T.
The various sclerotia, if kept moist, give rise to the fructifications of the fungi concerned, much as a potato tuber does to a potato plant, and in the same way the reserve materials are consumed.
A second edition of the Herbal was published in 1636 by Thomas Johnson, with a different illustration from that given in the first edition, and one which in some respects, as in showing the true nature of the tuber, is superior to the first.
489), has reviewed the tuber-bearing species of Solanum from a systematic point of view as well as from that of geographical distribution.
The six admitted tuber-bearing species are S.
The germinating spores are not only able to pierce the leaves and stems of the potato plant, and so gain an entry to its interior through the epidermis, but they are also able to pierce the skin of the tuber, especially in young examples.
The fungus, Sorosporium scabies, which is the cause of the scab, does not penetrate into the flesh of the tuber, nor detract from its edible properties.
These become brown, finally blackish and greatly contorted until a large scab is formed on the developing tuber, whence the name by which the disease is known - "black scab."
Introduced by Raleigh in 1610, the cultivation of this important tuber developed with extraordinary Depend- rapidity.
When the tuber of a potato begins to germinate the shoots which it puts out derive their food from the accumulated store of nutritive material which has been laid up in the cells of the tuber.
Many of the fruit-bodies have a pleasant flavour and are eaten under the name of truffles (Tuber brumale and other species).
Where the plant persists by means of a sympodial rhizome, or in Cyclamen by means of a tuber formed from the swollen hypocotyl.
An orchis found in the mountain yields the dried tuber which affords the nutritious mucilage called salep; a good deal of this goes to India.
The so-called fir-cone potatoes, which are elongated and provided with scales at more or less regular intervals, show also very clearly that the tuber is only a thickened branch with "eyes" set in regular order, as in an ordinary shoot.
The first signs of this fungus is the appearance of small white tufts of mycelium bursting through the skin of the tuber, the spores of the fungus being carried at the tips of the threads forming these tufts.