*Rhaponticum pulchrum.—A hardy perennial from the Caucasus, with numerous simple stems 2 ft. or more in height, and much-divided, undulating, toothed leaves of an ashy or sea-green colour on the upper side, and whitish underneath. The flowers are borne in small solitary purplish heads late in summer. A very suitable subject for embellishing dry, arid, rocky positions. R. scariosum is another kind, useful for the same purposes as the preceding species.
*THE RHUBARBS.
The Rhubarbs, from their vigour and picturesqueness, are well worthy of cultivation among hardy, fine-leaved plants. They are so hardy that they may be planted in any soil, and afterwards left to take care of themselves. Their fine leaves and bold habit make them valuable ornaments for the margins of shrubberies (the best way is to plant one singly a few feet from the margin of the shrubbery, so that when they die down in autumn no blank may be seen), and for semi-wild places where a very free and luxuriant type of vegetation is desired. Though not particular as to soil, they enjoy it when it is deep and rich, and the more it is made so the better they will grow.
Rheum Emodi is undoubtedly the handsomest and most distinct of the genus in cultivation. The figure conveys an accurate idea of the outline of its leaves, and of its aspect when in flower. The large leaves have their veins red, which distinguishes it from any other species. It has a large and deep-feeding root, black on the outside, and yellow within. The flowers are very small, of a yellowish white. It comes up somewhat later than the common kinds, and is not by any means common, though it may be found in botanic gardens and nurseries where collections of herbaceous plants are formed. It may, like all the species, be increased by division, but a young plant should not be disturbed for several years after being planted. It is a native of Nepaul.
The palmated rhubarb, Rheum palmatum, is immediately distinguished from its cultivated fellows by its leaves
being deeply cut into lobes. It is scarcely so ornamental or imposing as the fuller-leaved kinds, but is an interesting plant. I have seen it grown in some Irish gardens for culinary purposes, but do not remember to have noticed it in English kitchen-gardens. When well grown in deep and rather light and well-drained earth, the flowering-stem of this species attains a height of about nine feet. It is a native of Tartary, and well deserves a place. Rheum Ribes is a somewhat delicate species, a native of Southern Persia, which may be seen in one or two of our botanic gardens, and more frequently in those of France; but we fear it is not hardy enough to thrive well in these islands. The most remarkable known species is the Himalayan (R. nobile), which has its flower-stems beautifully clothed with large straw-coloured and pink-edged bracts, so as to form what may be termed a pyramid of leaves; but, as this species is not in cultivation, we need not describe it further. It would prove a very welcome addition to our collection of hardy plants.