POL 



POL 



parsed on the pistil when ripe, for the 

 purpose of impregnation. This dust is 

 commonly of a yellow colour, and is very 

 conspicuous in the tulip and lily. If this 

 powder is examined hy the microscope, 

 it will be found to assume some determi- 

 nate form, which often predominates, not 

 only through the different species of one 

 genus, but through all the genera of an 

 order. Being triturated in the stomach 

 of bees, by whom great quantities are 

 collected in the hairy brushes with which 

 their legs are covered, is supposed to 

 produce the wax. See WAX. 



POLL1A, in botany, a genus of the 

 Hexandria Monogynia class and order. 

 Natural order of J unci, Jussieu. Essential 

 character: corolla inferior, six-peialled ; 

 berry many -seeded. There is but one 

 species, viz. P. japonica. 



POLLICH1A, in botany, a genus of the 

 Monandria Monogynia class and order. 

 Natural order of Amaranthi, Jussieu. Es- 

 sential character: calyx one-leafed, five - 

 toothed; corolla five-petalled ; seed soli- 

 tary ; receptacle producing succulent 

 aggregate scales, sustaining the fruit. 

 There is but one species, viz. P. campes- 

 tris, whorled- leaved pollichia, a native of 

 the Cape of Good Hope. 



POLLUX, in astronomy, a fixed star of 

 the second magnitude in the constellation 

 gemini, or the twins. The same name is 

 also given to the himlerrnost twin, or pos- 

 terior part of the same constellation. 



POLYADELPHIA, in botany, a class 

 of plants, the eighteenth in order, whose 

 stamina are connected together at their 

 bases into several serieses. The plants 

 of this class are subdivided into orders, 

 according to the number of their stamina ; 

 thus the polyadelphia pentandria, con- 

 tain five stamina ; and the polyadclphia 

 icosandria and poly and ria, contain twenty 

 or more stamina. There are but few 

 genera included in this class. The cho- 

 colate-nut has five stamina, or rather five 

 bundles of stamina; each filament has 

 five anthers. Monsonia has fifteen sta- 

 mina in five bundles. The citron, lemon, 

 and orange, belonging to the genus citi-us, 

 have twenty stamina in several bundles. 

 The St. John's wort have many stamina 

 collected into five bundles. 



POLYANDRIA, in botany, a class of 

 plants, the thirteenth in order, with her- 

 maphrodite flowers, and a large number 

 of stamina in each ; these always exceed 

 the number of twelve, and grow on the 

 receptacle of the future seeds. By this 

 circumstance, chiefly, the class is dis- 

 tinguished from the ICCSAXURJ*. 



see. The most striking character ;s the 

 situation cf the stamina, which ;>re insert- 

 ed into the calyx or petals, or both. Tin's 

 is an unerring mark of distinction. Tiiis 

 class is subdivided into seven orders, from 

 the number of the styles; the poppy, 

 water-lily, &c. have one style ; the peony, 

 two; lark-spur, three ; tetraecra, four; 

 columbine, five ; water-soldier, six ; vir- 

 gin's bower, tulip-tree, &c. have many. 



POLYCARU1A, in botany, a g<;us of 

 the Pentandria Monogynia class and or- 

 der. Natural order of Dumoszc. Rhamni, 

 Jussieu. Essential character : petals five- 

 rounded ; stigma lobed ; capsule five- 

 celled, five-valved ; seeds arilled. There 

 is only one species, viz. P. madagascar- 

 ensis, a native of Madagascar, where it 

 was found by Commerson. 



POLYCARPON, in botany, a genus of 

 the Triandria Trigynia class and order. 

 Natural order of Caryophyllei. Essential 

 character: calyx five-leaved; petals five, 

 ovate, very small ; capsule one-celled, 

 three valved ; seeds very many. There 

 is only one species, viz. P. tetraphyllum, 

 four-leaved all-seed, a native of the; South 

 of Europe. 



PQLYCNEMUM, in botany, a genus of 

 the Triandria Monogynia class and order. 

 order of Holoraceae. Atriplices, 

 Jussieu. Essential character; calyx three- 

 leaved ; petals five, calycine ; seed one, 

 almost naked. There are five species. 



POLYGALA, in botany, mitkivort, a 

 genus of the. Diadelphia Octandria class 

 and order. Natural order of Lomentacese. 

 Pedicularcs, Jussieu. Essential charac- 

 ter : calyx live-leaved, with two of the 

 leaves shaped like wing's, and coloured; 

 legume obcordatc, two-celled. There are 

 forty-five species. 



POLYGAMIA, in botany, a class of 

 plants, the twenty-third in order, the 

 characters of which are, that they have 

 flowers of different structure : some hav- 

 ing male flowers, others female ones, and 

 others hermaphrodite. 



A polygamous plant must have some 

 of its flowers hermaphrodite. By this 

 circumstance its connection is cut off 

 with the plants of the classes monoecia, 

 and dioccia ; in the former of these the 

 plants are and roge nous, that is, bear male 

 and female flowers on the same root; in 

 the latter on different roots. 1. We have 

 instances of hermaphrodite and male 

 flowers on the same plant, in the white 

 hellebore, Sec. ; also in several of die um- 

 belliferous plants, as. the carrot, corian- 

 der, chervil, &c. 2. Instances of herma- 

 nhroditc and male flowers on distinct 



