commensal 



complementary 



the dual-lichen theory, where the 

 Fungus stimulates the host-Alga to 

 greater energy of function ; Com- 

 men'salism, the state in question. 



Com'missure, Coynmissu'ra (Lat., a joint 

 or seam), the face by which two 

 carpels adhere, as in TJmbelliferae ; 

 adj. commissu'ral ; '^ Corunm, the 

 central vascular strand in ferns ; <-- 

 Strand, the same structure ; -^ Sieve- 

 tubes, structures which unite the 

 different kinds of Sieve-tubes with 

 each other (A. Fischer). 



com'mon (Lat., covimu'nis), general or 

 principal, as opposed to partial ; --' 

 Bud, containing both leaves and 

 flowers, or more than one flower ; ~ 

 Bun'dles, those which are common 

 both to stem and leaf, being con- 

 tinuous from one to the other ; '^ 

 Ca'lyx X = Involucre; ~ Involu'cre, 

 that belonging to tlie main inflor- 

 escence, as of the general umbel; 

 — Name, one in popular use for a 

 plant, exclusive of the scientific 

 name ; ~ Ped'uncle, the main stalk, 

 when it supports several subordinate 

 ones, or pedicels ; -^ Per'ianth, 

 occnsionally used for the involucre, 

 as in Composita.e ; -^ Pet'iole, the 

 first and principal leaf-stalk in com- 

 ix)und leaves, the secondary petioles 

 being termed " partial "; '^ Eecept'- 

 acle, that which su})ports more than 

 one organ; --^ Um'bel = compound 

 Umbel. 



commu'nis (Lat.), growing in society; 

 not common, which is rendered by 

 vulgaris; Commu'nity, Clemen ts's 

 tenn for growths intermediate be- 

 tween Society and Family ; he 

 uses -AiiE to denote it. 



co'mose, covio-sus (Lat., with mucli 

 hair) , tufted, comate. 



Com'ospores (fV'?. the hair, -\- Spore), 

 seeds mancd or comate (Clements). 



compact', covipacl'us (Lat.), closely 

 joiiied or ])ressed together. 



Compa'go, pi. Compa'gines (Lat., a 

 connection) used by Wallroth m 

 speaking of the Lichcn-thallus 

 when more or less brittle or readily 

 parting into layers ; compagina'tus 



(Lat.), packed closely one over 

 another. 

 Compan 'ion-Cells, (1) in Phanerogams, 

 cells which are associated with 

 sieve -tubes and are of common 

 origin, filled with granular proteid 

 contents, and jjossessing strongly 

 marked nuclei; (2) Salmon's term 

 for Begleiter-Zellen, cf. Begleiter- 

 CELLs; ~ Hy'phae (y</)rj, a web), the 

 tip of the trichogyne of Polystigma 

 passing through a stoma into the air 

 is accompanied by slender mycelial 

 hyphae, which fonii a tuft, the 

 so-called companion hyphae (De 

 Bary). 

 Com'pass-plants, those which place 

 their leaves so that their surfaces 

 face east and west, the edges north 

 and south, such as Silphiicm lacinia- 

 tum, Linn. 

 Compensa'tion {compaisaiio, weighing 

 together) of Growth, used when the 

 development of a primordium of an 

 organ is sujipressed, or its growth 

 limited by another organ (Goebel). 

 Competit'ion {comj)ctitor, a rival), the 

 relation between plants occupying 

 the same area, and dependent upon 

 the same physical factors (Clements); 

 Competitive Society, applied to two 

 or more species whose roots occupy 

 the same level in the soil (Adamson). 

 comp'ital l^covi])lta'lii<, pertaining to 

 cross roads) in venation when the 

 veinlets angularly intersect ; also 

 when the sori are on the point of 

 junction. 

 com'planate, compliDia'tus (Lat., 



levelled), flattened, compressed, 

 complement'ary {compleraentum, that 

 which completes), when plants re- 

 ciprocallv help, as Mosses protect 

 soils and profit by shade and trees 

 above them ; -^ Cells, the com- 

 ponents of lentioel tissue arising 

 from the phellogen ; — chromatic 

 Adapta'tion, the power of Algae to 

 make efi*ective use of the light 

 which ivaches them, complementary 

 to their own coloration (Engel- 

 mann) ; -^ Soci'ety, two or more 

 species which loot at different levels 



86 



