AN ENCYCLOPADIA 
OF HORTICULTURE. 527 
ORNITHOPUS (frum ornis, ornithos, a bird, and 
pous, a foot; referring to the claw-like legumes or seed- 
pods). Bird's Foot. Including Astrolobium. ORD. Legu- 
minose. A genus comprising about seven species of 
small, low-growing, hardy annuals. Flowers small, pink, 
white, or yellow, in long peduncled heads or umbels. 
Leaves impari-pinnate. None of the species are worth 
growing for horticultural purposes. The genus is repre- 
sented in the British Flora by O. ebracteatus (from Scilly 
and the Channel Islands), with bright yellow flowers, 
veined with red, and O. perpusillus, a widely-distributed 
species, with white, red-veined flowers. 
. ORNITHOXANTHUM. A synonym of Gagea. 
ORNITROPHE. A Schmidelia 
(which see). 
ORNUS. Included under Fraxinus (which see). 
OROBANCHACEZ. An order of leafless, parasitic 
herbs, of various colours (never green), for the most 
part natives of Europe, North Africa, and extra-tropical 
Asia and North America, a few being found between 
the tropics in Asia, Africa, or mountainous or extra- 
tropical South America, and one in Europe and South 
Australia. Flowers hermaphrodite, regular, solitary in 
the axils of the bracts, sessile or pedunculate, few, or 
in dense, terminal, crowded spikes; calyx four or five- 
toothed or lobed; corolla lobes five, often broad, imbri- 
cated; stamens fcur, didynamous, inserted on the 
corolla tube. Scales alternate, densely crowded or 
scattered, upper ones bract-like. Stems or scapes erect, 
short or elongated, simple or slightly branched. Some 
of the species are agricultural pests, and do great 
damage, e.g., Orobanche pruinosa, on Beans; O. cruenta, 
on Saintfoin; O. minor, on Clover ; O. rubens, on Lucerne; 
Phelipæa ramosa, on Maize, Tobacco, and Hemp. The 
order comprises eleven genera (the best known being 
Orobanche) and about 150 species. 
OROBANCHE (the old Greek name used by Dios- 
corides, and said to be derived from Orobos, Vetch, and 
ancho, to strangle, because the species were supposed to 
kill the plants on which they grow). Broom Rape. 
ORD. Orobanchacee. A very large genus (above 150 
species have been described, but the number of those 
entitled to specific rank may be reduced to about 100, 
or less) of various-coloured plants, broadly dispersed 
_ over the Northern temperate regions of the Old World, 
rarely found in the tropics or the Southern hemisphere, 
and scarcely ever in America; six are natives of Britain. 
Flowers at the axils of the scales, sessile or sub-sessile, 
bibracteolate or ebracteolate, densely or interruptedly 
spicate. Scales often acute. The species have no horti- 
cultural value. They are, however, decidedly interesting 
plants; the annual species may be sown together with 
the seeds of the host plants they particularly affect. 
Those of perennial duration should be sown near their 
special host plants; as, however, three years elapse 
before the young parasites arrive at the flowering stage, 
it is better to fence off the places where they are sown, 
and not disturb the’ ground. 7 
OROBELLA. Included under Vicia (which see). 
OROBUS (the old Greek name used by Theo- 
phrastus; it has nothing to do with the present 
genus). Bitter Vetch. ORD. Leguminose. An exten- 
sive genus of usually hardy, herbaceous perennials, 
mostly natives of the Northern hemisphere, and now 
included (by Bentham and Hooker) as a section of 
Lathyrus, from which it differs in having no tendril at 
the tip of the petiole. For horticultural purposes, how- 
ever, the two genera are here kept distinct. Many 
Species are very handsome; they thrive in almost any 
soil, and are readily increased by dividing the tufted 
rootstocks in spring. Some force readily, and make 
synonym of 
O. niger (black). 
Orobus—continued. 
charming pot plants for cool-house decoration. The 
species here described are those generally found in 
gardens. i 
O. atropurpureus (dark-purple). A synonym of Vicia sicula. 
O. aurantius (orange-coloured).* fl. deep yellow; 3 
elongated, shorter than the leaves. June. ‘J. with five or six 
airs of lanceolate, bluntish leaflets. Stems simple, angular. 
12 ft. Caucasus, 1818. (S. B. F. G. ser. ii. 198.) 
O. canescens (canescent). A synonym of O. filiformis. 
O. filiformis (thread-formed). f. white, with a tinge of blue; 
peduncles many-flowered, longer than the leaves. May. J. with 
usually two or three pairs of linear, bluntish, pubescent or 
dotted leaflets. Stem tetragonal. h. 14ft. South zurope, 1816, 
Syn, O. canescens. (B. M. $117.) 
O. Fischeri (Fischer's). A synonym of Vicia sicula, 
O. flaccidus (flaccid).* fl. purple; vexillum with two prominent 
obtuse teeth near the middle, which embrace the inner petals; 
peduncles terminal or axillary. May. l. remote, spreading, 
two or three pairs of opposite, very long, linear, attenuated, 
labrous leaflets, dark green above, paler beneath; stipules 
— semi-sagittate. Stem erect. h. 6ft. Croatia, &c. (B. M. 
2937, under name of O. stipulaceus, and wrongly ascribed to 
North America.) 7 i 
O. hirsutus (hairy). f. red; racemes axillary, twice as long as 
the leaves, few-flowered. May. J. ovate, acute, with parallel 
nerves. h. Thrace, &., 1822. (B. M. 2345; S. B. F. G. 
ser. ii. 302.) 
O. luteus (yellow). f. yellow; uncles elongated, many- 
flowered, about equal in length othe leaves. June, l 
three to five pairs of elliptic-lanceolate, mucronulate leaflets, 
which are glaucous beneath. Stems simple, angular. A. lft. to 
2ft. Europe, 1759. (L. B. C. 783; S. B. F. G. ser. ii. 115.) 
purple; peduncles many. flowered, lo: 
than the leaves. June. /., leaflets elliptic, mucronulate, 
almost parallel nerves. h. 3ft. 
Sy. En. B. 407.) 
o. pann 
from white and cream ti 
fellow ; peduncles many-tlowered, longer than the leaves, May. 
7 with two or three pairs of linear, mucronate leaflets. Stem 
simple. h.1ft. South Europe, 1794. (J. F. A. 39; S. B. F. G. 22.) 
0. varius (various. flowered) fl. with the standard rose- 
soloai; and the keel and wings yellowish; peduncles many- 
flowered, longer than the leaves. May. l. with three or four 
pairs of linear-lanceolate, mucronulate leaflets. Stems simple, 
angular. A. 1ift. Italy, 1759. (B. M. 675.) 
O. sessilifolius (stalkless-leaved). fl. ps in few-foweređ 
racemes. May. l, leaflets narrow, dark green, almost sessile. 
h. lft. Greece, &c., 1823. (B. M. 2796; S. F. G. 692.) 
. variegatus (variegated). fl. finely variegated, small. Early 
33 wich Ewo ii three pairs of lanceolate leaflets. Stems 
simple, flexuous. k. 1ft. Europe, 1821. (S. B. F. G. ser. ii. 28.) 
O. vernus (spring).* fl. purple and blue, with red veins, the keel 
tinted on 1p tg the whole changing to blue, secund, nodding ; 
uncles axillary, many-flowered, shorter than the leaves, 
pring. L. with two or three ma of ovate-lanceolate, acuminate, 
shining leatlets. Stems simple, flexuous. h. lft, Europe, 1629. 
(B. M. 521; S. F. G. 691.) : 
ORONTIEÆ. A tribe of Aroideæ (Araceæ). 
ORONTIUM (the old Greek name for a plant said 
to grow on the banks of the river Orontes). ORD. Aroideæ 
(Araceæ). A monotypic genus, the species being a hardy 
aquatic perennial, with a deep rootstock. This should 
be planted in open water, from 6in. to 12in. beneath 
the surface. Propagated by divisions. 
ticum (aquatic). fl. ect, crowded all over the narrow 
gy which 8 9 scape; lower ones with 
six concave sepals and six stamens, upper ones four; 
incomplete and distant. May. /r. a green utricle. J. entire, 
ts ag ae ey long-petioled. North America, (H. E. F. 19; 
I. B. G. 4 
OROPHOMA. Included under Mauritia (which 
see). 
OROTHAMNUS. Included under Mimetes (which 
see). 
OROXYLUM (from oros, a mountain, and zylon, 
wood; referring to the habitat). Orp. Bignoniacee. A 
monotypic genus, the species being a glabrous stove 
tree, which requires almost unlimited root space for its 
successful cultivation; it does best when planted out in 
a well-drained, prepared border of turfy loam, leaf mould, 
and sand, and the long shoots trained near the glass. 
Europe (Britain). (B. M. 2261; 
+ 
