AND GENERAL HORTICULTURE. 



341 



POL 



Marattiacece, etc., in -which the ring is abso- 

 lutely -wanting, are called Exannulate. 

 Polypo'dium. Polypody. From poly, many, 

 and poits, a foot; referring to its numerous 

 root-like feet. Nat. Ord. Polypodiacem. 



A very extensive and interesting genus 

 containing many hardy and robust growing 

 native species, as well as the most delicate 

 and choice of the cultivated Ferns. It in- 

 cludes plants of two different modes of 

 growth, each series comprising a number 

 of species of different kinds of venation, 

 and from all climates. The sori is round, 

 rarely oblong, and is borne on the back 

 of the lobes of the frond. The following 

 may be selected as among the best known and 

 most largely cultivated of the green-house 

 sorts. P. ang)istatum. P. argutum, P. aureuin 

 (sj-n. Phlebodium aureutn), P. Billardieri, P. 

 Broumii, P. Catharina:, P. crenatiiin (syn. 

 Goniophlebium), P. CyathecFfoliiim, P. decurrens, 

 P.dilitatum.P. Fraxinifolium, P. gluucophyllum, 

 P. Henchmanni, P. JuglandifoUum, P. lingua 

 (sj'n. Nijihobolus), P. lucidum, P. mncrodon, 

 P. morbillosum, P. Paradisea}, P. jjectinatum, P. 

 plumosum, P. Phyllitidi'^, P. subauriculafum, P. 

 vacciniifolium, and many others. Of tlie hardy 

 species the following will be found most use- 

 ful for the Fernery or rock-garden, especially 

 as some of them are evergreen. P. achrosti- 

 choides, P. alpestre (a species much resemb- 

 ling the Lady-Fern, Aspleiiium Filix-FcEmiyia), 

 P.Californicum, P. Dryopteris, P. Phegopteris, P. 

 trichodes (syn. Lastrcea tenericaulis), and P. 

 vulgare, with its many elegant varieties, P. 

 V. camhricum, P. v. elegantissimum, etc. This 

 genus has been so divided up by various bot- 

 anists that it is hard to tell under which 

 genera to find the various species. The fol- 

 lowing genera, with some others, are now by 

 many botanists included under Polypodium, 

 Aglaomorpha, Campyloneuron, Cryptosorus, 

 Dictymia, Dictyopteris, Drynaria, Goniophle- 

 bium, Goniopteris, Lepicystis, Microgramme, 

 Niphobolus, Phegopteris, Phlebodium, Phy- 

 matodes, Pleopeltis, Pseudathyrium, etc. 

 The various species require good drainage 

 and plenty of water while growing, with a 

 temperature proportionate to that of the 

 country from which they have been intro- 

 duced. They are all easily increased by 

 division, or from spores. 



Polypody. See Polypodium. 



Polypo'gon. Beard Grass. From poly, many, 

 and jJoyoH, a beard. Nat. Ord Graminacece. 



A small genus of handsome grasses, 

 sparingly met in the older settled parts of 

 this country, having become naturalized from 

 Europe. They have no agricultural value. 



Polyse'palous. Having many separate sepals. 



Polysta'chya. From poly, many, and siachys, a 

 spike ; alluding to tlie inflorescence of some 

 of the species, Nat. Ord. OrchidacecB. 



A genus of about forty species of epiphytal 

 Orchids, natives of Africa, India, the Malayan 

 Archipelago, and tropical America. This is 

 an interesting genus much resembling, and 

 requiring the same treatment as Burlingtonia. 

 P. bracleosa. P. hypocrita, and P. rufinida, are 

 the best known and most desirable species. 



Poly'stichiun. From poly, many, and stichtis, a 

 row ; numerous rows of spore cases. Nat. 

 Ord. PolypodiacecE. 



PON 



A genus of Ferns, formerly included in 

 Aspidium, and requiring the same general 

 treatment. 



Poly'xena. Named after Polyxena, the daugh- 

 ter of Priam. Nat. Ord. Liliacew. 



A genus of South African bulbous plants, 

 now included by some as a section of Mas- 

 sonia. P. odorata, and P. pygmcEa, the only 

 species of interest, have small white, deli- 

 ciously, sweet-scented, Hyacinth-like flowers 

 in dense corymbs. They are cultivated more 

 for curiosity than for their beauty. 



Pomaceae. A natural order included under 

 Rosaceoe. 



Pomade'rris. From poma, a lid, and derris, a 

 skin ; alluding to the membraneous covering 

 of the capsule. Nat. Ord. Rhamnacete. 



A genus of erect, branching, woolly shrubs, 

 natives of Australia and New Zealand, with 

 star-like hairs and alternate, entire, or tooth- 

 ed leaves. Several species are in cultivation, 

 pi'oducing a profusion of small yellowish- 

 brown or whitish flowers. M. apetala, forms 

 a small tree, and yields a close-grained wood, 

 called Cooper's wood, and Victorian Hazel. 



Poma'ria. Named after Pomar, a Spanish phy- 

 sician. Nat. Ord. Lcguminosce. 



A genus of green-house shrubs, mostly 

 South American. P. glandidosa, with yellow 

 flowers in axillary racemes, is the only intro- 

 duced species. This genus is now included 

 by Bentham and Hooker under Ctesalpinia. 



Po'max. From poma, an operculum or lid ; 

 referring to the operculum of the fruit. Nat. 

 Ord. RubiacecB. 



P. umbellata, introduced from Australia in 

 1826, is an interesting green-house shrub, 

 with greenish white flowers. It is often 

 found in cultivation under the name of P. 

 hirta, or Opercularia umbellata. 



Pome. A fleshy, many-celled fruit, as an Apple. 



Pomegranate. See Punica granatum. 



Pond Lily. See Nymplusa. 



Pond Weed. The genus Potamogeton. 



Ponga'mia. Pongam is the Malabar name of 

 P. glabra. Nat. Ord. Leguminosce. 



P. glabra, the only described species, is an 

 evergreen, green-house shrub with white 

 flowers, which have a showy red calj'x, and 

 are borne in loose axillary racemes, three to 

 five inches long. From the seeds of this tree 

 an oil called Kurungi or Poonga Oil, is ex- 

 tracted in India, which is largely used by the 

 poor classes for burning. 



Pontede'ria. Pickerel Weed. Named after J. 

 Pontedera, Professor of Botany at Padua. 

 Nat. Ord. Pontederiacece. 



A genus of native aquatic plants, common 

 in the borders of ponds or creeks. P. cordata, 

 our common Pickerel Weed, is a beautiful 

 plant, with arrow-shaped leaves, producing, 

 in July, long spikes of intense blue flowers. 

 This species can be grown easily in tubs on 

 the lawn, in the same manner as the common • 

 "Water JAly (XymphtBa odorata). This genus is 

 now placed under Eichhornea, by some 

 authors. 



Pontederia'ceae. A small natural order of erect 

 or floating aquatic herbs, mostly natives of 

 America. It comprises four genera, Eich- 

 hornea, Heteranthera, Monochoria, and Ponie- 

 deria, and over thirty species. 



