Pneumathodinm 



polar 



(2) an IeratinCt Root, as. in Taxo- 

 dium ; pneumat'ic Tis'sue, open 

 tissue containing much air (Kearney) ; 

 Pneu'mato - ehymif'era [Va'sa] X, 

 spiral vessels (Lindley) ; Pneu'- 

 matode (65os, a way), any opening 

 of the nature of a lenticel or stoma 

 (Jost) ; Pneu'matophore, Pneumato- 

 ph'orum (^opew, I carry), (1) used of 

 air-vessels of any description, as 

 tracheids ; (2) intercellular spaces in 

 Rhizophoreae (Karsten) ; (3) X ^^^ 

 membranous tube of a spiral vessel 

 (Lindley^ ; pneumatotac'tic [raKriKhs, 

 apt for arrangement), applied to 

 those zoospores whose irritability is 

 dependent on the presence of dis- 

 solved gases, the products of 

 respiration of the zoospores in the 

 sporangium (Hartog) ; Pneumato- 

 tax'y, the condition de?-.ribed ; 

 neg'ative '^ , the irritability which 

 determines the escape of certain 

 spores, as in Achlya ; Pneama- 

 tof'erus (fero, I bear), the external 

 membranous tube of spiral vessels 

 (J. S. Henslow). 



Pnoi'um {irj/oif, a blast), a succession of 

 plants on seolian (drifting) soils, 

 such as blown sand (Clements). 



Po'ad {v6a, meadow, + ad), a meadow 

 plant (Clements). 



PocilluB, pi. Pocil'li {pocillum, a 

 little cup), the scyphi of Cladonia, 

 so termed by Nylander. 



Pock'et, of Lemna, a hollow in the 

 leaf, whence a new leaf arises 

 (Potter) ; '-' -leaves, specialized 

 leaves which collect humus ; 

 Mantle-leaves ; — plums = Bag- 

 plums ; Pock'eting, applied to an 

 intrusion of cortex (Lang). 



poc'nliform, pocicliform'is {poctilnmy a 

 cup ; forma, shape), shaped like a 

 goblet or drinking-cup. 



PomI, a dry and many-seeded dehiscent 

 fruit, a legume or silique ; <- -like, 

 applied to such fruits as those of 

 CorydaliSf ITypecoum, and Cleome. 



pode'tiiform ( + Podetium from itovs, 

 iroSbs, a foot ; forma, shape), shaped 

 like a podetium ; Pode'tium, (1) a 

 stalk-like elevation rising from the 



thallus and supporting an apothe- 

 cium in some Lichens ; (2) also 

 applied to the support of the capi- 

 tulum of Marchantia ; and (3) the 

 seta of Mosses ; Pode'ta J is given 

 by Lindley as a synonym. 



podicellate, Leighton's term for 

 stalked, as applied to Lichens, 



Podicil'lum t. a very short podetium 

 (Lindley) ; Pod'ium, Pod'us, a foot- 

 stalk or similar support ; Pod'ocarp, 

 Podocar'pus {Kafnrhs, fruit), a stipi- 

 tate fruit, that is, when the ovary 

 is borne by a gynoph^re ; podo- 

 ceph'alous, -liis {K€<po\^, a head), 

 with a pedunculate head ; Podo- 

 gjyn'ium {yw^, a woman), an eleva- 

 tipn in the centre of a flower which 

 carries the ovary, a gynopliore ; adj. 

 podogyn'icuB, podog'ynus ; podop'- 

 terous {iTTfphv, a wing), having 

 winged peduncles (Orozier) ; Pod'o- 

 sperm, Podoeper'mium, -ma{<Tie4piM, 

 a seed), the stalk of a seed, the 

 funicle. 



poecilothenn'io = poikilothermic. 



Po'gon (7rw7«»', a beard), used in com- 



f>osition to denote any collection of 

 ong hairs. 



poikilodynam'io {tr oikIkot, various;' 

 Zvvaixis, power), in hybrids when 

 the character of one parent 'is 

 practically absent ; poikilother'mic 

 {dfpfjLT], heat), rising and falling in 

 response to varying temperature 

 (Jones). 



Point'al, an old term for Pistil ; 

 pointless, muticous ; pointletted, 

 apiculate. 



Point'er Cell, an English equivalent 

 for Deuter Zell. 



Poi'um {ir6a, meadow), (1) a plant asso- 

 ciation in which Poa is a predomi- 

 nant genus (Oanong) ; (2) a meadow 

 formation (Clements). 



Polache'na, Polacke'na, Polake'nium 

 (iroXvs, many ; o, without ; xo^""* 

 I gape), Richard's term for a fruit 

 like a cremocarp, but composed of 

 five carpels, cf Pentachenium. 



po'lar (irAos, a pivot), (1) relating to 

 the poles of an organ ; (2) derived 

 from the smaller ends of a flattened 



U 



293 



