R. pachyptera (thick-winged); Bot.  Mag. 2820.—­Stem woody; branches jointed, flattened as in Phyllocactus, with deep notches; width of joints, 2 in. or more.  Flowers small, yellowish-white, borne singly in the notches in November.  Fruit a small, white berry, rarely ripened.  A sturdy, comparatively uninteresting stove plant, introduced from Brazil in 1830.  Syn.  Cactus alatus.

R. paradoxa (paradoxical).—­Stems trailing, with numerous long branches of most extraordinary form.  Imagine a three-angled, fleshy branch, often several feet in length, the angles winged, about 1/2 in. deep, green, with smooth, reddish margins.  At intervals of about 2 in. the branch has the appearance of having been twisted half round.  There is no other plant with branches anything like these.  Flowers produced in November, in the apex of the interrupted angles, small, white.  Fruit seldom ripened.  A native of Brazil, whence it was introduced in 1837.  There is a fine example of this trained along a rafter in the Succulent-house at Kew.  The numerous branches hang down several feet from the rafter, and have a most extraordinary appearance.  This species requires stove treatment.

R. penduliflora (pendulous-flowered).—­A small, thin-stemmed plant, with smooth, green branches, no thicker than whipcord, and numerous fascicled or clustered, small joints, 1/2 in. long, green, with red dots, angular when young.  Flowers on the tips of the terminal joints, pale yellow, 1/2 in. across, developing in August.  Fruit white, Mistletoe-like.  This species was introduced from tropical America in 1877, and requires stove treatment.

R. p. laxa (loose).—­This variety has the branches curving, and more pendulous; in other respects it resembles the type, and requires the same treatment.

R. pentaptera (five-winged).—­Stems erect; branches stiff, long-jointed, with five wing-like angles, slightly spiral, the angles notched at intervals of 1 in.  Flowers in the notches, 1/2 in. across, white, produced in August.  Fruit a white, Mistletoe-like berry.  A curious plant from Brazil, and introduced in 1836.  In stove temperature it forms a compact pot-shrub, 2 ft. high, and is worth growing on account of its singular stems.

R. rhombea (diamond-branched).—­Stems and branches as in R. crispata, but without the wavy margins, and with more elongated joints.  Flowers small, white, produced in the notches of the joints in November.  Fruit a shining, milk-white berry.  A compact plant from Brazil, worth growing for its bright green, leaf-like stems.  It should be grown in pots, in stove temperature, and encouraged to form a globose bush.

R. Saglionis (Saglio’s); Bot.  Mag. 4039.—­A tiny plant, similar in habit to R. penduliflora, but with brown branches, the small joints angled, and bearing silky hairs.  The branches and joints are set at zigzag angles.  Flowers pale yellow, produced in autumn on the younger joints.  Fruits white, Mistletoe-like.  A small, delicate plant from Buenos Ayres, not more than 6 in. high.  This species requires stove treatment.