196 



THE DICTIONARY OF GARDENING, 



Polyporus continued. 



by one side to the trunk of the tree. They often con- 

 tinue to grow slowly for many years, and reach a size 

 of from lin. or 2in. to 3ft. across, by several inches 

 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 pilous 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 E. 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 rddiciperda), on various trees, by 

 P. fulvus on the Silver Fir, by P. borealie on the 

 Spruce, by P. vaporarius on Spruce and Firs, by 

 P. mollis on Firs, by P. igniarius on numerous forest- 

 trees (Dicotyledons) and fruit-trees, by P. dryadeus on 

 Oaks, and by P. sulphurous 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. 



FOLYPREMUM (of Adanson). A synonym of 

 Valerianella (which see). 



POLYPTERIS (of Nuttall). Included under Fala- 

 fozia (which see). 



FOLYSFORA. Included under Gordonia (which 

 see). 



POLYSTACHYA (from poly, many, and stachys, a 

 spike ; alluding to the inflorescence of some of the species). 

 STNS. Encyclia, Epiphora. ORD. Orchidecn. A genus com- 

 prising about forty species 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 

 int a sheath. The species are rather interesting plants. 

 Those best known to cultivation are described below; 

 they require culture similar to Burlinetonia (which 

 see). 



P. bracteosa (bracted). JL yellow ; sepals brown at base ; Up 

 broadly oblong, revolute, the lateral lobes brown within ; bracts 

 lanceolate, acuminate, concave, at length leafy ; raceme nodding, 

 pubescent. I. solitary, petiolate, oblong-ovate, acute. Pseudo' 

 bulbs almost round, compressed, aggregate. Sierra Leone, 1838. 

 (B. M. 4161.) 



P. galeata (helmet-shaped). /., perigone green, spotted with 

 rea; sepals mucronate ; petals minute, oblong-spathulate ; lip 

 greenish-white, fleshy, trilobed, the middle lobe cordate, acute 

 peduncles terminal, generally one-flowered. I. linear-oblong, 

 ,%* ,IS eudo J bulbs small > one-leaved. Sierra Leone, 1837. 

 (B. M. 3707, under name of P. grandiflora.) 



P. hypocrita (hypocritical), ft. light green, with a few brown 

 spots at the base of the blunt chin ; lip whitish, mealy, the 



Polystachya continued. 



middle lobe very much crisped. Western tropical Africa, 1882. 



This species is very similar to P. luteola, but larger. 

 P. lineata (lined). A. greenish, striped with brown, minute, 



disposed in spikes. 1. linear-ligulate. Pseudo-bulbs pyriform. 



Guatemala, 1870. (Ref. B. 80.) The Mexican variety, elatwr, is 



rather larger in all its parts. (Ref. B. 81.) 

 P. luteola (yellowish). A. yellowish-green, minute, disposed in 



oblong, remote, dense-flowered spikelets, lin. to 3in. long. 



I. 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). A. green, pubescent, disposed in 



paniculate, thyrsiform spikes. I. lanceolate, seven-nerved, longer 



than the scape. Pseudo-bulbs ovate. Sierra Leone, 1822. (B. R. 



851.) 

 P. pubescens (pubescent). /. bright yellow, streaked with red, 



few, fragrant, terminating an ancipitous, flexuous scape ; lip 



small, trident-shaped, bearded on the inside with long hairs. 



(B. M. 5586.) 



P. rufinula (reddish), ft. in a few-flowered, simple, slightly 



I. binate, oblorig-linear, flat. Delagoa Bay, 1838. 

 SYN. Epiphora pubescens. 



. unua res, . n a ew-owere, smpe, sgy 

 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 

 fragile hairs. I. narrow-ligulate, blunt, in pairs at the flowering 

 season. Pseudo-bulbs stick-like, thickened at base, 2in. or less 

 long. Zanzibar, 1879. 



POLYSTICHUM. Included under Aspidium (which 

 see). 



POLYTJENIUM. Included under Antrophyum. 



POLYTHRIX. A synonym of Crossandra (which 

 see). 



FOIiYXENA (named after Polyxena, the daughter of 

 Priam, beloved by Achilles). STNS. Manlilia, Polyantlies 

 (of Jacquin). ORD. Liliacece. 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. pygmaia, the only species which call for men- 

 tion here, require culture similar to Massonia (which 

 see). 

 P. odorata (odorous). A. white, small, Hyacinth-like, deliriously 



sweet-scented, disposed in a dense corymb, which is seated 



between the pair of leaves. October. I. erect, lanceolate, 3in. to 



Sin. high. 1871. A pretty plant. (B. M. 5891, under name of 



Massonia odorata.) 

 P. pygmsea (pigmy). This is the correct name of the plant 



described in this work under name of Massonia ensifolia. 



POLYZONE. A synonym of Darwinia. 

 FOMACEJE. Included under Rosaceae. 

 FOMADERRIS (from poma, a lid, and derris, a skin ; 

 alluding to the membranous covering of the capsule). ORD. 

 Rhamnece. 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. andromedrefolia (Andromeda-leaved). A synonym of P 



phillyreoides. 



P. apctala (apetalous).* Victorian Hazel. /. greenish, small, and 

 very numerous, in loose, oblong, thyrsoid panicles, leafy at the 

 base ; calyx stellately hairy ; petals none. June. I. petiolate, 

 ovate-lanceolate or broadly oblong, obtuse or rarely acute, 2in. to 

 4in. long, irregularly crenulate, glabrous, but rough and much 



