312 
THE DICTIONARY OF GARDENING, 
— 
ROELLA (named in honour of William Roell, Pro- 
fessor of Anatomy at Amsterdam). Orp. Oampanulacee. 
A genus comprising eleven species of greenhouse, rigid 
sub-shrubs or small, diffuse herbs, confined to South 
Africa. Flowers sessile within the imbricating leaves, 
solitary or glomerate; calyx with an adnate, oblong or 
cylindrical tube and a five-parted limb, the lobes often 
toothed ; corolla campanulate or funnel-shaped, five-lobed. 
Leaves scattered, small or narrow, often rather rigid 
and fascicled at the axils, entire or ciliate - toothed. 
Several of the species have been introduced, but that 
described below is the most desirable. A compost of 
sandy loam and peat is most suitable for its culture. 
Propagation may be effected by seeds; or by young 
cuttings, which will root freely in the soil above-named, 
if a hand glass be placed over them. 
R. ciliata (ciliated-leaved). African Harebell. f. solitary, ter- 
minal; corolla white at base, with a deep purple circle, above 
i e violet, girded by white, the lobes —— September. 
tverect, linear, acuminated, ciliated ; upper ones longer. h. 6in. 
to12in. 1774. (B: M. 378; F. d. S. 517; L. B. C. 1156.) 
RÆMERIA (named in honour of John James Roemer, 
1763-1819, Professor of Botany at Landshut, and author 
of several botanical works). Syn. Romeria. OBD. Papa- 
veracee. A genus comprising only two species (and 
these, perhaps, varieties of one) of very pretty, hardy, 
annual herbs. Seeds should be sown in the open 
border, in spring, where the plants are to remain. 
R. hybrida (hybrid). Violet-flowered Horned Poppy; Wind 
Rose. fl. violet-purple with a black disk ; sepals hairy. May and 
June. Capsules 2in. to šin. long, cylindric, hispid above. 1. once 
or twice pinnatitid ; segments tipped by a bristle. Stem erect. 
h. 2ft. South and West Europe, &c. (Britain). This plant has the 
habit of Papaver Argemone. (Sy. En. B. 64.) Syn. R. refracta. 
R. refracta (bent back). A synonym of R. hybrida. 
REMERIA (of Trattinick). A synonym of Steri- 
phoma (which see). 
RG@PERA. Included under Zygophyllum (which 
see). 
ROEZLIA (named in honour of Roezl, a well-known 
collector, who travelled in Mexico, Central America, &c.). 
ORD. Melastomacee. A monotypic genus. The species 
is an erect, stove shrub, requiring culture similar to 
Monochetum (which see). 
granadensis (New Granada).* fl. carmine-purple ; calyx red, 
four-lobed ; petals four, roundish-ovate, emarginate ; stamens 
four; panicles terminal, many-flowered; peduncles glabrous or 
nearly so. Autumn. J. opposite, petiolate, ovate-lanceolate, 
hairy on both sides, entire, five to seven-nerved. Branches sub- 
angular. h. about 3ft. New Granada. (R. G. 706.) 
R. regia (royal). A synonym of Furcrea Bedinghausii. 
ROGATION FLOWER. See Polygala vulgaris. 
ROGIERA. Included under Rondeletia (which 
see). 
ROHDEA (named in honour of Mich. Rohde, phy- 
sician and botanist, of Bremen). Syn. Titragyne. ORD. 
Liliacee. A monotypic genus. The species is a green- 
house or half-hardy, perennial, with a short, thick rhizome. 
For culture, see Reineckea. : 
R. japonica (Japanese). f., perianth white, fleshy, jin. long and 
thick ; spike very dense, lin. to 2in. long. January to April. 
T all radical, nine to twelve in a rosette, sub-erect, sessile, ob- 
lanceolate, 1ft. long, 2in. to din. broad, glabrous, acute. h. 2ft. 
Japan, 1783. (B. M. 898, under name of Orontium japonicum.) 
ROHRIA. A synonym of Berkheya. 
ROLANDREA (named in honour of Daniel Rolander, 
a pupil of Linneus, who visited Surinam). ORD. Com- 
posite. A monotypic genus. The species is a green- 
house, evergreen shrub, with inconspicuous, white flower- 
heads and penniveined leaves, native of tropical America, 
It is probably lost to cultivation. 
ROLLERS AND ROLLING. For keeping walks 
firm and in good condition, an iron Roller is requisite in 
gardens. The size must be determined by the extent 
and width of the walks to be Rolled. New gravel 
walks should always have a light Roller passed over them 
Rollers and Rolling—continued. _ 
first, and a heavy one afterwards. Others, if they are 
firm, and have been well made in the first place, should 
bear a heavy weight always. Rollers of almost any size 
may be obtained in iron up to several hundredweights. 
Rolling should only be practised when walks are suffi- 
ciently dry to keep the gravel from clinging; the proper 
time frequently does not last long, and, when walks are 
rough, an opportunity for Rolling them should not be lost. 
ROMANA. A synonym of Buddleia. 
ROMANZOFFIA (named in honour of Count Ro- 
manzov, a Russian nobleman, who was a patron of scien- 
tific studies). ORD. Hydrophyllacew. A genus consist- 
ing of only two species of low, tufted, hardy perennial 
herbs, having much the appearance of Saxifrages; they 
inhabit the sub-arctic regions of Eastern Asia and 
Western America. Flowers white, unilaterally racemose ; 
calyx segments five; corolla broadly or tubularly cam- 
panulate with five imbricated, spreading lobes; stamens 
five, affixed to the base of the corolla. Radical leaves 
long-stalked, cauline ones very few, orbicular-reniform, 
deeply toothed. R. sitchensis, the only species intro- 
duced, is a suitable subject for planting on rockwork. 
It requires much the same culture as Saxifraga (which 
see). 
R. sitchensis (Sitcha).* Sitka Water Leaf. f. white; corolla 
nearly thrice the length of the calyx ; peduncles straight. April. 
l. long-stalked, somewhat rounded-reniform in shape. h. 4in. 
Sitcha, 1873. (B. M. 6109; R. G. 748.) 
ROMERIA. A synonym of Remeria (which see). 
ROMNEYA (named after the Rev. Dr. T. Romney 
_Robinson, an astronomer, of Armagh). ORD. Papa- 
veracee. A monotypic genus. The species is a tall, showy, 
branched, glabrous, herbaceous perennial, allied to Platy- 
stigma. Although a half-hardy plant, it nevertheless 
thrives best, and produces larger and more abundant 
flowers if allowed space in a cool greenhouse. A rich, 
sandy loam soil is most suitable. The species may be 
increased by means of seeds, sown in the spring. 
R. Coulteri (Coulter’s).* f. white, showy, terminating the 
branches, corymbose or solitary ; sepals three, scarcely lin. long ; 
— six, biseriate, 2}in. long, broadly obovate, thickened at the 
; Stamens very numerous, many-seriate. Summer. J. petio- 
late, glabrous, glaucous, pinnatifid, setose-ciliated on the margins ; 
lower segments linear-lanceolate, upper ones deltoid ; petioles 
one-fourth the length of the leaves. h. 2ft. to4ft. California, — 
1875. (F.M. 252; G. C. n. s., iii. 280 ; Gn. xi. 374; R. G. 1876, 152.) 
ROMULEA (a name commemorative of Romulus, 
the mythical founder of Rome). Syn. Trichonema. In- 
cluding Spatalanthus. ORD. Irideew. A genus of pretty, 
greenhouse or hardy, bulbous plants, natives of Western 
Europe, the Mediterranean region, and South and West 
Africa. Fifty-four species have been enumerated, but, 
according to the authors of the ‘Genera Plantarum,” 
many of these are reducible to mere varieties. Mr. Baker, 
in his review of the genus published in the “Journal of 
the Linnean Society,” xvi. 86, accords specific rank to 
thirty-six. Flowers one to a spathe, sub-sessile or 
shortly pedicellate; perianth funnel-shaped, with a very 
short, or rarely elongated, tube, and equal, erecto-patent, 
entire lobes; stamens affixed to the throat; spathes long- 
pedunculate in the axils of the floral leaves; bracts 
beneath the ovary at the apex of the pedicel shorter, and 
sometimes broader, -than the spathe. Radical leaves 
linear, sometimes subulate, the sheaths rarely lanceo- 
late-dilated ; cauline leaves similar, but smaller. The 
species described below are those best known to cultiva- 
tion. They require to be planted out in a pit or frame, 
in a compost of sandy loam and peat. Propagation may 
be effected by offsets. 
R. bulbocodioides (Bulbocodium-like). /. ish- = - 
| spathe valve perpe hanne ar aag Ros a aa — and — 
striped; scape terete, two-sheathed. June. l, radical ones 
fistular-sheathing ; cauline ones binate, in threes, or rarely 
solitary, alternating with the peduncles. A. 6in. Cape of Good 
Hope, 1810. — (B. M. 1392, under name of — 
