THE DICTIONARY 
OF GARDENING, : 
Polyporus—continued. 
by one side to the trunk of the tree. 
tinue to grow slowly for many years, and reach a size 
of from lin. or 2in. to 3ft. across, by several inches 
They often con- 
in thickness in the middle. From their dry texture, it 
is easy to preserve them as herbarium specimens; but 
insects are very apt to eat and destroy them when 
dried. Old trees of various kinds very frequently have 
Fungi of this genus growing on their stems, the mycelium 
penetrating and drawing nourishment from the wood, 
and the pileus often remaining for many years on the 
stem, very often near its base. It seems probable that 
the species of Polyporus do not live on quite healthy 
trees, but on those already weakened by some other 
cause. Our knowledge of their importance as parasites 
is due largely to R. Hartig, the well-known authority 
on the diseases of forest-trees. He has traced and 
described the effects produced by P. annosus, Fr. (under 
the name of Trametes radiciperda), on various trees, by 
P. fulvus on the Silver Fir, by P. borealis on the 
Spruce, by P. vaporarius on Spruce and Firs, by 
P. mollis on Firs, by P. igniarius on numerous forest- 
trees (Dicotyledons) and frnit-trees, by P. dryadeus on 
Oaks, and by P. sulphureus on many forest-trees (Dico- 
tyledons) and on Pear-trees. Numerous other instances 
of parasitism could be added. Further details need not 
here be entered into, it being sufficient to say that the 
species of Polyporus are not of frequent occurrence in 
gardens and pleasure-grounds. The wood diseased by 
the presence of the Fungus becomes soft and rotten, and 
a tree infested with Polyporus may be regarded as 
doomed, sooner or later, to perish from the action of the 
Fungus on the wood. It is well, if the tree can be at 
once removed, to cut it down and have it used as fire- 
wood, rather than to allow the Fungus to distribute its 
myriads of spores to injure other trees. 
POLYPREMUM (of Adanson). 
Valerianella (which see). 
POLYPTERIS (of Nuttall). 
- foxia (which see). 
POLYSPORA. Included under Gordonia (which 
see). 
POLYSTACHYA (from poly, many, and stachys, a 
spike; alluding to the inflorescence of some of the species). 
Syns. Encyclia, Epiphora. ORD. Orchidew. A genus com- 
prising about forty spécies of stove, epiphytal orchids, 
mostly tropical and South African, a few being found 
in India, Malaya, and tropical America. Flowers usually 
small; sepals connivent or almost spreading, the dorsal 
one free, the lateral ones sometimes much broader, adnate 
to the foot of the column; petals similar to the dorsal 
-sepal, or narrower ; lateral lobes of lip somewhat prominent, 
erect, the middle one spreading or recurved, and un- 
divided; column sometimes very short; pollen masses, 
four; racemes many, short, forming a loose, narrow panicle, 
or solitary and simple, on a leafy stem ; peduncle terminal. 
_ Leaves few, distichous, oblong or narrow, base contracted 
into a sheath. The species are rather interesting plants. 
Those best known to cultivation are described below; 
be require culture similar to Burlingtonia (which 
see). 
= P, bracteosa llow ; se . 
el” (bi yellow ; sepals brown at base; lip 
F + * N 
A synonym of 
Included under Pala- 
racted). fi 
r M oblong, revolute, the lateral lobes brown within ; bracts 
olate, acuminate, concave, at length leafy ; raceme nodding, 
—— —— —— acute. Pseudo- 
GM. 353 ẽo pressed, aggr regate. Sierra Leone, 1838, 
P. ga 
Polystachya—continued. 
middle lobe very much crisped. Western tropical Africa, 1882. 
This species is gx similar to P. luteola, but larger. 
P. lineata (lined). ^. greenish, striped with brown, minute, 
disposed A ——— l. linear-ligulate. Pseudo-bulbs pyriform. 
Guatemala, 1870. (Ref. B. 80.) The Mexican variety, elatior, is 
rather larger in all its parts. (Ref. B. 81.) 
P. luteola (yellowish). 4. yellowish-green, minute, disposed in 
oblong, remote, dense-fiowered spikelets, lin. to Sin. long. 
k oblong-lanceolate, acute, plicate, many-nerved, sheathed at 
base, distichous, shorter than the scape, recurved at apex. Stem 
thickened at base. Mexico, 1818. (H. E. F. 103.) SYN. Den- 
drobium polystachyon (L. B. C. 428; L. C. B. 20). 
P. puberula (puberulous). f. green, pubescent, disposed in 
paniculate, thyrsiform spikes. l. lanceolate, seven-nerved, longer 
D the scape. Pseudo-bulbs ovate. Sierra Leone, 1822. (B. R. 
P. pubescens (pubescent). jl. bright yellow, streaked with red, 
few, fragrant, i i 
rminating an ancipitous, flexuous scape; lip 
small, trident-shaped, bearded on the inside with long hairs. 
l. binate, oblong-linear, flat. Delagoa Bay, 1838. (B. M. 
‘Syn. Epiphora pubescens. 
P. rufinula (reddish). A. in a few-flowered, simple, slightly 
hairy raceme; sepals cinnamon-brown outside, greenish inside, 
washed with light brown on the borders; petals greenish, with 
brown tips; lip yellowish on disk, the front borders light purple, 
with a rather long ridge, and the furfuraceous surface caused by 
e hairs, J, narrow-ligulate, blunt, in paire at the flowering 
season. Pseudo-bulbs stick-like, thickened at base, 2in. or less 
long. Zanzibar, 1879. 
POLYSTICHUM. Included under Aspidium (which 
see). 
POLYTZ:NIUM. Included under Antrophyum. 
—— A synonym of Crossandra (which 
see). 
POLYXENA (named after Polyxena, the daughter of 
Priam, beloved by Achilles). Syns. Manlilia, Polyanthes 
(of Jacquin). ORD. Liliacee. A genus comprising about 
seven species of greenhouse, South African, bulbous plants, 
included, by Mr. Baker, as a section of Massonia. Flowers 
sometimes very short, sometimes long, loosely spicate or 
racemose; perianth tube cylindrical or slightly swollen 
above; lobes six, sub-equal, much shorter than the tube; 
scape simple below the inflorescence, short; racemes fre- 
quently shorter than the leaves. Radical leaves two, 
spreading or erect, sub-sessile or petiolate. P. odorata 
and P: pygmæa, the only species which call for men- 
* here, require culture similar to Massonia (which 
see). 
P, odorata (odorous). 
. white, small, Hyacinth-like, deliciously 
sweet-scented, í in a dense corymb, which is seated 
between the of leaves. October. l. erect, lanceolate, 3in. to 
5in. hi 1871. A t f 
— Le pretty plant. (B. M. 5891, under name o 
P. Ls 
described in Man i — — pi oe — ——— pen 
POLYZONE. A synonym of Darwinia. 
POMACEÆ. Included under Rosaceæ. 
POMADERRIS (from poma, a lid, and derris, a skin; 
alluding to the membranous covering of the capsule). ORD. 
Rhamnee. A genus comprising eighteen species of green- © 
house, evergreen shrubs, natives of the Southern or Eastern 
regions of Australia, or of New Zealand. Flowers pedi- 
cellate, in small, umbel-like cymes, usually forming terminal — 
panicles or corymbs, or rarely solitary in the axils of the 
leaves; calyx five-lobed, deciduous or reflexed; petals 
concave or nearly flat, or none. Leaves alternate, penni- 
veined; under surface, as well as the branches, white, 
hoary, or rusty with tomentum, often mixed with, or con- 
cealed by, silky hairs. The species thrive in a compost of 
peat and sandy loam. Propagation may be effected by 
cuttings of half-ripened shoots, cut to a joint, dried at the 
base, and inserted in sand, under a glass. _ 
P, Sonu ee (Andromeda-leaved). A synonym of r 
P. apetala (apetalous).* Victorian 
Hazel. R; 
very numerous, in Pied 
tae eniya lat ry i petals nome June” 
hiar $ or ` obtuse 
