Phytodichogamy 



Plakea 



Dichogamy ; Phytoecorogy ( + 

 Ecology), the relation of a plant 

 to its environment ; Phytoflagella'ta 

 ( -f Flagellata), the initial plant ; 

 a unicellular ciliate alga (Jameson) ; 

 Phytoaageriida, Deiage's name for 

 flagellates ; Phytogeograph'ical 



Forma'tion, Grisebach's early term, 

 changed to Vegetative Formation 

 by Warming ; Phyt'oid, the in- 

 dividual unit in a plant-colony 

 (Child) : Phytom'eter, plants counted 

 as single or in groups (Clements) ; 

 adj. phytomet'ric ; Phytom'etry, 

 the process in question ; Phyto- 

 monad'ina (Minchin) = Phyto- 

 flagellata ; Phytomorphorogy, the 

 science of plant -form and structure 

 (Ball); Phytopathorogist {-ndOos, 

 suffering ; Adyoj, discourse), a 

 student of plant diseases ; Phyto- 

 pathoi'ogy is the study ; Phyto- 

 physiorogy, cf. Physiology ; Phyto- 

 proteran'dry (+ Proterandry), 

 the stamens ripe before the styles 

 are receptive ; Phytoproterog'yny, 

 the styles mature before the 

 stamens have ripe pollen ; Phyto- 

 sociolog'ical {socin-s, a companion), 

 plant -sociology, a branch of ecology 

 devoted to consideration of vege- 

 tation rather than the habitat 

 factors, this being Geobotany; 

 Phytosociorogy, the condition under 

 review may be divided into (a) 

 Autecology, the relation between 

 the individual and its habitat ; 



(b) Autochorology, local botany ; 



(c) Autogenetics, the change of 

 floras; further, {d) Synecology, 

 the relations betAveen the plant 

 association and the habitat ; (e) 

 Synechorol'ogy, the distribution 

 of plant associations, and (/) Syn- 

 genetics, change of plant asso- 

 ciations (Riibel) ; Phytost'erol 

 (oreap, fat), derived from plants, 

 resembling cholesterol, which is 

 formed by animals ; Phytotaxo- 

 n'omy (to^i?, order), systematics 

 of plants, described in terms of 

 arrangement ; Phytotbariea {daXXos, 

 a young twig), the origin of the 



vegetable phylum (Janet) ; phyto- 

 tom'ic, adj. of Ph^totomh- ; Phyto- 

 zo'&, add, (2)= Flagellata ; Phy'to- 

 zo'o-flag'ellate, the initial organ- 

 ism (Janet). 



Pig'ment-spot, in the motile algae, 

 a red spot, commonly called the 

 " Eye-spot." 



Pil'lar, an old term for Stipe (2). 



Pine'tum, an association of Pinus 

 Linn. ; ~ cladino'sum, with the 

 soil covered with Cladonia Hill ; 

 '~ herb'idum, grasses clothing the 

 soil; ~ hylocomio'sum, with 

 masses of mosses Hylocomium 

 Bruch et Schimp. and Dicranum 

 Hedw. (Warming). 



Pin'na-bar, c/. Pinna Trace Bar. 



Pi'noid (ef§o9, form), a conifer with 

 characteristic dry cones and wind- 

 dispersed seeds (Church). 



Pi'oneer Stage, towards a climax, 

 " the extreme condition of a 

 primary area," as lichens for rock 

 seres and submerged plants for 

 water seres (Clements). 



pionno'tal, a continuous spore layer, 

 as in the fungal genus Picranoies Fr. 



Pistie'tum, an association of Pistia 

 Linn. 



Pis'tillode, Pistillo'dium (+ Pistil), 

 a rudimentary pistil in the male 

 flowers of such genera as Elatostema 

 Forst. ; cf. Staminode. 



Pit'ting, the presence of pits in the 

 tracheids of conifers, further char- 

 acterized as alterna'ting ~ ; op'po- 

 site ~ ; ra'dial ~, or tangen'tial ~ ; 

 Pits, locally thin parts in cell- walls, 

 corresponding with similar places 

 in neighbouring cells ; Air ~, 

 have no counterpart on the side 

 of the air space (Jeffrey). 



Placo'diomorph ifiop<f>rj, shape), used 

 of a polarilociilar spore, as in the 

 lichen Placodium DC. 



Pla'cula [TrXaKovs, a flat cake), a stage 

 of Volvoz with four plastids in a 

 plane ; adj. plac'ular (Janet). 



Plagiot'ropy, cf. Plagiotropism. 



Plak'ea (tj-Aol^, flat), a tabular colony 

 of phytoflagellates in a single 

 layer (Janet). 



457 



