897 



POLLACK. 



POLYGONUM. 



393 



Silica . 



Alumina 



Lime 



Oxide of Iron 



83-5 

 4-0 

 8-5 

 1-6 



Water 9'0 



106-6 



The silica is apparently derived from Diastomaceee. [DIASTOMACE.E.] 



POLLACK. [MERLANGUS.] 



POLLEN. [STAMEN.] 



POLLEN. [BEE.] 



PO'LLIA (Gray), a genus of Molliuca. 



POLLI'CIPES. [ClBRIPEDIA.] 



POLLONTES (De Montfort), a genus of Foraminifera. 



POLLUX, a Mineral containing Silica, Potaah, and Soda. 



POLYADE'LPHIA, the name given by Linnaeus to the eighteenth 

 class of his Sexual System. It was so named from iroAtk, many, and 

 ao(\rf)ij!, a brother, in alluaiou to the stamens being collected into 

 several parcels. 



POLYA'NDRIA, the name given by Linnxus to the fourteenth 

 class of his Sexual System. Although the name means literally many 

 stamens or males, yet it is applied, in a restricted sense, to those plants 

 only which have many stamens arising immediately from below the 

 ovary. 



POLYANTHUS, a garden variety of the Oxlip Primrose, with 

 brown flowers, is one of those plants which have from time imme- 

 morial been favourites in gardens. It was probably obtained by acci- 

 dent, and is now propagated either by seeds or division of its root. 



POLYANTHUS NARCISSUS is the ffareiuut Tazxtta. [NARCISSUS.] 



POLYBASITE. [SILVER.] 



POLY'BIUS. [PORTUNIDJB.] 



POLY'BORUS. [FALCONID.E.] 



POLYBRACHIONA. [ACALEPH.E.] 



POLYBRANCHIATA, M. De Blaiuville's name for his second order 

 of Paracephulophora ifonoica, consisting of the families Telracera/a 

 and Sicerata. The first of these families consists of the genera 

 Glaucut, Laniogerui, Tergipei, Carolina, and Eolidia ; the second, of 

 the genera ScyUcea, Tritonia, and Tetkys. [NUDIBRASCHIATA.] 



POLYCARPON (from iroAu, many, and xdpros, a seed or fruit : 

 seeds numerous), a genus of Plants belonging to the natural order 

 Paronycliiacea. The sepals are slightly coherent at the base ; the petals 

 5 and emarginate ; the stamens 3-5 ; styles short and 3 in number. 

 The fruit is a 1-celled, 3-valved, and many-seeded capsule. 



P. tetraphyllum has triandrous leaves, emarginate petals, the stem- 

 leaves in fours, and the leaves on the branches opposite. In young 

 plants the leaves are often all opposite. It is a native of the coasts of 

 the south-west of England, of Europe, and the Canary Islands. 



There are two other species of Polyearpan : P. filtinefolium, an 

 inhabitant of Europe, the Cape of Good Hope, and Holland; and 

 P. peploidet, a native of Sicily and France. 



(Babington, Manual of British Botany.) 



POLY'CERA. [NUDIBRANCHIATA.] 



PO'LYCHRUS. [IOCANID.S.] 



POLYCOTYLEDONOUS PLANTS are those which have more 



than two cotyledons. Instances of this occur in the Cruciferce, in 



'/'urn, and Schizopetalum ; in the Boraginacece order, in Amrinkia; 



and especially in Coniferous plants. All such plants are referred to 



the Dicotyledonous type. [SEED.] 



POLYCRASE. [YTTRIUM.] 



POLYDECTUS, a genus of Cnutacea. [COHTSTES.] 



POLYDONTES (De Montfort), a genus of Hdicidcc. 



POLYERGUS, a genus of Pormindct, separated from Formica by 

 Latreille. The type of the genus is P. rufacent, the Amazon Ant. 

 The species are destitute of stings, and have the antennae near the 

 mouth and the mandibles narrow, curved, or very much hooked. The 

 habits of the Amazon Ant, P. ru.fuc.ent, are very remarkable, the neuters 

 of this species unite with those of Formica tanguinea in making 

 war upon the neuters of other species of Pormicida, especially P. 

 cunicularia and P. futca. The result of the conquest is the making 

 slaves of the latter, who are always found doing the hard work of 

 the colonies of their enslavers. [ANT.] 



POLYGALA, a genus of Plants belonging to the natural order 

 Polyyalacece. It has five persistent sepals, the alto large and petaloid ; 

 petals three, their claws all united with the stameniferous tube, the 

 lower ones carinate (keel-shaped), the two additional ones abortive ; 

 stamens united into a tube at the base, which is cleft in front; anthers 

 opening by a pore ; ovary 2-celled ; ovules solitary, pendulous from the 

 apex of the cell ; capsule 2, locular, loculicidal, compressed ; seeds pen- 

 dulous from the apex of the cells, pubescent, with a carunculate arillus 

 at the hilum ; albumen abundant, fleshy. The species are shrubs or her- 

 baceous plants. The flowers arranged in terminal or axillary racemes. 



P. Senega, Virginian Snake-Root, a perennial plant, native of 

 several parts of North America, but the best is found in Virginia, 

 having a rootstock, about the thickness of a quill, twisted, and gene- 

 rally branched, the rootlets being esteemed the most powerful part 

 in meiliciii*-. The leaves are alternate, sessile, lanceolate, with a 

 sharpish -point, smooth, paler underneath; flowers white, in a close 

 terminal spike; sepals 5 ; corolla small, closed, having two obtuse 

 lateral segments, and a short crested extremity. 



P. vulgaris, Milkwort, a British species. It has a crested keel; 

 flowers in a terminal raceme; wings of calyx obovate, mucronate; 

 lateral bracts longer than pedicels; lower leaves smaller than the 

 upper. It is found in dry pastures. P. calcarea is a second British 

 species. 



P. nMfo is found in dry gravelly soils in many parts of the United 

 States. It is used in medicine as a tonic. 



There are 14 species of Polygala found on the continent of Europe, 

 mentioned in Wood's 'Tourist's Flora.' 



POLYGALACE^E, Milkwortt, a natural order of Exogenous 

 Plants. The species are herbs or shrubs with simple exstipulate 

 leaves ; the pedicels have three bracts, and the flowers are irregular, 

 unsymmetrical, and falsely papilionaceous ; sepals five, irregular, odd 

 one posterior, two inner ones (wings) usually petaloid ; petals more 

 or less united, usually three, of which one (the keel) is anterior, larger, 

 and sometimes crested ; stamens six or eight, usually combined into 

 a tube, which is split on the upper side; anthers 1-celled, opening by 

 pores ; ovary usually 2-celled, with a single pendulous anatropal 

 ovule in each cell ; style curved ; capsule flattened, with albumiuous 

 carunculate seeds, containing a straight embryo. The order is con- 

 sidered by St. Hilaire and others as allied to Sapindacece, and some 

 authors place it near Leguminosce, from which it differs in its hypo- 

 gonous stamens, and in the odd sepal being superior, and the odd petal 

 inferior. The plants are scattered all over the globe. There are 

 about 500 known species. The genera are Salomonia, Polygala, 

 Alundia, and Securidaca. They are generally bitter and acrid, and 

 the roots yield a milky juice. (Balfour, Clatsbook of Botany.) 



POLYGAMIA, a Linnsean class of Plants in which the species have 

 male and hermaphrodite, or female and hermaphrodite, or both female, 

 male, and hermaphrodite flowers on the same or different individuals. 



POLYGASTRICA. [INFUSORIA.] 



POLYGONA'CE/E, Buckwheats, a natural order of Apetalous Plants 

 with triangular fruit and usually with stipules united into a tube or 

 ocrea, through which the stem passes. Their fruit is composed of 

 three aspermous carpellary leaves joined by their edges, and surround- 

 ing a single erect ovule deriving its origin from a central placenta; 

 and it proves the truth of the modern theory, that in many cases 

 the ovules derive their origin immediately from the centre of vege- 

 tation, or the growing point, and not from the margin of carpellary 

 leaves. The order consists of herbaceous plants more frequently than 

 of shrubs, and a large part of them are mere weeds ; as for example 

 our docks, and wild polygonums ; some however are handsome flowers, 

 as the P. orientate, or Garden Persicaria, and P. amplexicaule [PoLT- 

 OONUM]; others are valuable for cooking, as the rhubarb, whose roots 

 also furnish the important tonic and purgative drug of that name, and 

 in some a great quantity of astringent matter is found, as in the 

 Coccoloba uvifera, or Seaside Grape of Jamaica, from which a kind 

 of Kino has been prepared. [COCCOLOBA.] A species of Indian Poly- 

 gonum, P. tinctorium, has recently been introduced into cultivation in 

 Belgium as a substitute for indigo. The flour of the seeds of P. 

 tartaricum, P. Fagopyrum, and others, is made into a bad kind of 

 bread in Lombardy and other countries. [PoLYGONUM.] 



The genus Rheum also belongs to this order. [RHEUM.] 



POLY'GONUM (the Greek iroKvyovov, ' much productive"), a genus 

 of Plants belonging to the natural order Polygonaceae. It has a 5-partod 

 perianth, from five to eight stamens, and from two to three styles ; a 

 1 -seeded trigonous or compressed nut, lateral incurved embryo, the 

 cotyledons not contorted. This is a very extensive genus, containing 

 the Knotgrasses, Bistorts, Persicarias, and Buckwheats of our own 

 waysides, fields, and gardens. They grow in almost any soil, some 

 being aquatic, and others flourishing in sandy sterile tracts. 



P. Butorta, Snake- Weed, has a dense spike, ovate-subcordate leaves, 

 the radical leaves with winged foot-stalks, the stamens half as long 

 again as the perianth, the nut triquetrous, its faces ovate, smooth. 

 The calyx is rose-coloured and deeply 5-cleft, obtuse, and spreading. 

 The fruit is black and shining. This plant is one of the most power- 

 ful vegetable astringents, its root contains tannin and gallic acid in 

 abundance ; a decoction of it is employed in gleet and leucorrhoea as 

 an injection, as a gargle in sore throats, and as a lotion to ulcers 

 attended with excessive discharge. Internally it has been used com- 

 bined with gentian in intermittents. It may also be employed in 

 passive haemorrhages and diarrhoea. [BISTORT, in ARTS AND Sc. Div.] 



P. amphibium has a dense ovate cylindrical spike, stalked ovate- 

 oblong floating leaves, a compressed smooth shining nut, five stamens, 

 and a creeping root. The flowers are of a bright crimson colour. It 

 is a native of England in ponds, ditches, and wet places. It is a fine 

 showy plant, but one of the most difficult to eradicate from lands 

 recovered from rivers or drained lakes and marshes. The subaquatic 

 stems root at every joint, and extend to a surprising length, rising 

 through the soil. They bear some resemblance to sarsaparilla, and 

 according to Coste and Willemet they are substituted for this drug 

 by the herbalists of Nancy; these authors also report that the 

 apothecaries and druggists of Lorraine give it the preference. 



P. hydropiper, the Water-Pepper, has drooping filiform interrupted 

 spikes, lanceolate wavy leaves, glandular perianths, a large compressed 

 nut, its faces ovate, acute, and of a purplish-black colour. It is a hot 

 acrid plant, and is reputed to be a powerful diuretic, but it loses its 

 activity by drying, and therefore requires to be used in a fresh state. 



