Operculum 



OF BOTANICAL TERMS. 



Oscillating' 



OPER'CtJLUM, (1) a transversely- 

 dehiscent lid or cap, like that 

 covering the capsule of many 

 mosses; (2) the lid of a pitcher- 

 shaped leaf. 



OPlS'THODAL, posterior; applied 

 to the inner or posterior open- 

 ing of a stoma. Compare 

 Eisodal. 



OP'PO§lTE, opposed in position. 

 Said, for example, of leaves 

 when situated over against 

 each other in pairs at the 

 same height upon the stem. 

 One floral organ, however, is 

 opposite another when it is 

 superposed to it, i.e., when it 

 stands between it and the axis. 

 Compare Alternate. 



OPPOsfTiFLO'ROUS, having op- 

 posite peduncles. 



6PP6§lTlFO'LIOtJS, (1) having 

 opposite leaves; adversifolious; 

 (2) situated opposite a leaf, as 

 the tendrils in the grape. 



OP'POSlTELt-PfN'NATE, having 

 leaflets in pairs. 



ORBiCULAR, circular in outline, 

 or nearly so; orbiculate. 



dRBIC'ULATE, see Orbicular. 



ORDER, a division of a class con- 

 taining one or more genera; 

 family. 



OR'DInAL, pertaining to an 

 order. 



OR GAN, any part having a spe- 

 cial function, as a leaf or sta- 

 men. Compare Member. 



ORGANIC gEN'TRE, a point or 

 axis around which growth 

 takes place. It may not re- 

 main the mathematical centre. 



ORGAnOG ENS', the origin and 

 development of organs; organ- 

 ogenesis. 



6RGAN6G'RAPHt, the study of 

 organs. 



ORGANOPLASTY, having the 



power of producing organs, 

 as organoplasty tissue. 



6R'GAN§ OF REPRODUCTION, 



those whose chief function is 

 to serve directly or indirectly 

 in the production of seeds or 

 spores. In the higher plants 

 the stamens and pistils are 

 usually indicated by the term. 



Organs, of VEGETATION, 



those which minister to the 

 growth of the whole plant: 

 roots, stem, and leaves. 



ORIENTATION, strictly, facing 

 the east. Used in horticulture 

 for the setting of transplanted 

 trees facing the same way as 

 they stood originally. Used 

 in botany for assuming any 

 definite direction with respect 

 to the points of the compass or 

 to the axis of the plant or or- 

 gan. 



6RM0G0N, see Hormogonium. 



ORTHOPLO gEOUS, having con- 

 duplicate cotyledons. (Obs.) 



ORTHOS Tl€HY, a vertical row 

 of organs. Compare Para- 

 stichy. 



6RTH0s'TOMOUS, having a 

 straight opening. 



ORTHOT'ROPAL, see Orthot- 

 ropous. 



ORTHOTROP'IC, growing erect, 

 as stems in contrast with 

 leaves, etc. Compare Pla- 

 giotropic 



ORTHOT'ROPOtJS, (1) applied to 

 an ovule or seed in which the 

 hilum coincides with the cha- 

 laza and the micropyle occu- 

 pies the apex opposite. Com- 

 pare Anatropous. (2) Applied 

 to the embryo it means the 

 opposite of antitropous, i.e., 

 having the radicle next the 

 hilum, as in anatropous seeds. 



OS'glLLATJNG, see Versatile. 

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