= 
AN ENCYCLOPAEDIA OF HORTICULTURE. 
Guatteria—continued. 
ornamental stove evergreen trees or shrubs, all natives 
of the warmer parts of the New World. Flowers yellowish- 
white, greenish, or dusky; peduncles one-flowered, axillary 
or lateral, solitary or fasciculated. Leaves feather-nerved, 
alternate, entire, exstipulate. Guatterias thrive in a com- 
post of loam, peat, and sand. Propagation is readily 
effected by cuttings, inserted in sand, under a glass, in heat. 
Probably G. Ouregou is the only species in cultivation. 
G. Ouregou (Ouregou). M., peduncles axillary, short, two to 
four; calyx segments triangular, pointed ; petals rusty-velvety, 
obovate, interior longer; carpids ovoid, 2. obovate-oblong, 
cuspidate, cuneate at the base, shining above, glabrescent be- 
neath ; veins prominent. Caribbean Islands. A tall tree. SYN. 
Anona chrysopetala. 
GUAVA. See Psidium pyriferum. 
GUAZUMA (name of Mexican origin, employed by 
Plumier). Bastard Cedar. Syns. Bubroma and Diuro- 
glossum. ORD. Sterculiacee. A genus containing about 
five species of ornaméntal stove evergreen trees, natives 
of the tropical regions of both hemispheres. Flowers 
small; cymes axillary, shortly pedunculate. Leaves un- 
equally dentate, often oblique. The species thrive in a 
compost of peat and loam. Cuttings of ripened shoots 
root freely in sand, under a glass, in heat. 
Gs ulmifolia (Elm-leaved). fl., petals yellow, with two purple 
“awns at the apex. August. h. 40ft. to 60ft. A wide-spreading 
tree, not unlike the Elm, with leaves that sleep hanging quite down, 
p 
: whilst the petioles remain entirely stiff and straight. West 
i Indies, 1739. SYN. Bubroma Guazuma. 
GUELDER ROSE. See Viburnum Opulus. 
GUERNSEY LILY. See Nerine sarniensis. 
GUETTARDA (named in honour of John Etienne 
Guettard, 1715-1786, member of the Academy of Sciences 
at Paris, who published, in 1747, catalogue of the 
plants growing in the vicinity of Estampes). Including 
Cadamba and Laugeria. ORD. Rubiacee. A genus 
containing about fifty species of ornamental stove ever- 
green shrubs or small trees, natives chiefly of tropical 
America. Flowers sessile and unilateral along the branches 
of the peduncles, and solitary in the forks; corolla salver- 
shaped, with a cylindrical tube, and from four to nine 
oval-oblong lobes; peduncles axillary, bifid. Leaves 
ovate or lanceolate. Guettardas succeed best in peat and 
loam mixed. Propagated by cuttings, inserted in sand, in 
heat. é 
G. odorata (sweet-scented).* fl. reddish, nearly lin. long, villous 
on the outside, very sweet-scented at night; cymes bifid. Sum- 
mer, J. oval, acute at both ends. A. 6ft. to 10ft. Tropical 
America, 1818. Shrub. 
G. rugosa (wrinkled). A synonym of G. scabra. 
G. scabra (scabrous). M. white; peduncles compressed, villous, 
almost four times longer than the petioles. /. obovate, mucronate, 
coriaceous, scabrous above, reticulated and pubescent beneath ; 
stipules lanceolate, acuminated, caducous. West Indies, 1818. 
SYN. G. rugosa. : 
G. speciosa (showy). fl. white, exquisitely fragrant, partaking 
much of the scent of cloves, large; cymes pedunculate, velvety, 
much shorter than the leaves. June and July. l. broad, ovate or 
obovate, downy beneath. Branches horizontal, forming a large 
shady head. k. 30ft. Tropical Asia, 1771. ‘Tree. (B. R. 1393.) 
GUEVINA (the native name). Syn. Quadria. ORD. 
Proteacee. A monotypic genus. The species is a 
greenhouse evergreen tree, succeeding in a peat and 
loam soil. Propagated by cuttings, inserted in sand, 
under a glass, 
G. Avellana (nut . white, hermaphrodite, geminate, pedi- 
cellate, wane * Foy a long axillary racemes ; perianth tube 
cylindrical; limb ovoid, recurved. June. fr. coral-red when 
Fe about the size of a cherry. Seed edible, largely used by the 
Chilians. Z. alternate, impari-pinnate ; leaflets dentate. A. 40ft. 
1826. This tree is hardy in the 
(in its native country), Chili, 
South-west of England. 
GUICHENOTIA (named in honour of Antoine 
Guichenot, a French gardener and traveller). Including 
Sarotes. ORD. Sterculiacee. A genus containing about 
half-a-dozen species of greenhouse shrubs, confined to 
extra-tropical Australia. Flowers nodding, solitary, or 
~ «One point concerning the spread of this disease seems 
y T] 
101 
Guichenotia—continued. 
shortly racemose ; calyx five-lobed; petals five, small and 
scale-like. Leaves narrow, entire, with revolute margins. 
Guichenotias succeed in a loamy-peat soil. Propagated 
by cuttings. ‘The two species here described are probably 
the only ones yet: introduced. 
G. ledifolia (Ledum-leaved). /l. white ; racemes several-flowered ; 
calyx scarcel membranous, tomentose, the three prominent ribs 
on each sepal giving it a rigid, striate appearance. Spring. J, on 
very short petioles, joblong-linear, obtuse, mostly lin. to 1}in, 
long; margins much revolute, wrinkled, thick, and soft; stipules 
similar, but usually rather shorter and more sessile, 1868, SYN. 
Lasiopetalum Baueri, of gardens, 
G. macrantha (large-flowered). 
racemes of two or three. Marc 
ledifolia. 1847. (B. M. 4651.) : 
GUILANDINA. Included under Cwsalpinia. - 
GUILIELMA (named in honour of Queen Frederica 
Guilielma [Wilhelmine] Carolina of Bavaria). ORD. 
Palme. A genus (included, by Bentham and Hooker, 
under Bactris) containing three species of elegant stove 
palms, confined to the tropical regions of South 
America. Flower-spike branched. Fruit ovate, about 
the size of a peach, produced in large pendulous 
bunches. Leaves pinnate, hairy; leaflets and footstalks 
spiny. Trunk slender, marked with circular scars, and 
armed with exceedingly sharp spines. For culture, see 
. purple, large, pendulous, in 
L ressmbiing those of G. 
G. speciosa (showy).* l. 2ft. to 4ft. long, ; pinne about 
lit. long, lin, wide, apex broader, bifid, deep green nerves onthe __ Se 
upper sides clothed with slender black bristles ; petioles broad] m 
sheathing at the base, thickly armed with slender long black : 
sharp spines. Stem tall, densely spiny, slender. Amazon. SYN. 
Bactris Gasipaés. ` 
G. utilis (useful). f. monæcious. Seeds edible, having the 
flavour of chestnuts. l, young ones broad and bitid, bristling 
with short spines, which spring from the ribs or veins, the 
ridges of the upper surface and the costa beneath being the 
parts furnished) with them; mature ones forming a handsome 
Trunk slender, spiny. 
pinnate head; petioles densely spiny. 
Costa Rica, 1873. (G. C. 1873, 1271.) 
GUINEA PEACH. See Sarcocephalus. 
GUM AMMONIAC. See Dorema Ammoniacum. 
GUM CISTUS. See Cistus ladaniferus. 
GUM ELEMI. The gum-resin of Amyris Plu- 
mieri (which see), &c. = 
GUMMING. See Gummosis. 
GUMMOSIS, or GUMMING. Recent observations | 
on this highly contagious disease have shown that it is 
caused by a fungus, which has been named by Professor tee 
Oudemans Coryneum Beijerinckii. The mycelium of this = 
fungus appears to develop a ferment which penetrates — — 
the adjacent cells and transforms the cell - walls, the 
starch granules, and other cell contents into gum, 
whether these cells belong to the host plant or to the 
fungus, The ferment of the Coryneum can penetrate 
into living cells—eg., those of cambium—and can 
modify their protoplasm so that the cells that they 
afterwards produce by division form a tissue with new 
properties. This tissue is the pathological wood 
parenchyma, Sooner or later, this tissue begins, in turn, 
to secrete the ferment, and to change into gum. The 
quantity of ferment so formed is greater than the 
amount originally present in the diseased cells. Gum- 
ming can be propagated from diseased to healthy i 
places without mycelium extending from one to the 
other. The action resembles the propagation that albi- 
notic parts exercise on healthy ones. It is conjectured 
that the channel of propagation is the phloem, and 
that the contagion is the ferment. In other cases, the 
mycelium of the Coryneum is the exciting cause of — 
Gumming. A similar disease produces gum arabic, gum 
aéanth, and, probably, many resins and gum resins, 
clear—the fungus itself cannot penetrate the bark: there 
must be some abrasion or laceration of the latter before 
the germ tubes can enter. These injuries may clearly 
