GLOSSARY 323 



thini'um (0ts, ^ivo's, a dune), a dune formation; thinad, a dune plant. 

 tiphi'um (tic^o?, pool), a pool formation; tiphad, a pond plant. 

 tiri'um (rcipa), rub away), a bad land formation; tirad, a bad land plant. 

 tonoboie (twos, tension), a plant whose seeds are scattered by projection 



from calyx or involucre. 

 transect {transedus, cut through), a cross-section of vegetation. 

 trechometer {rpix^. to run off), an instrument for measuring run-of!. 

 tribi'um {jpi^ui, wear or rub away), a succession in an eroded soil. 



umbrinus, umber. 



variable, able to produce variants; variant, a form arising from origin by 

 variation; variation, the origin of new forms by the action of selection 

 upon minute differences. 



vegetation form, a characteristic plant form, e. g. , tree, rosette, etc. 



vernal, pertaining to spring. 



vicine {yicinus, neighboring), invading from adjacent formations. 



viridis, green. 



vixgregarious, arranged in small or indistinct groups. 



water-content, the water of the soil or habitat; physiological, the available 

 soil water; physical, the total amount of soil water. 



xenodoche {iivo%, strange), an anomalous succession. 



xerad (^T/pos, dry), a xerophyte; xerasi'um (irjpaaia, drought), a succession 

 due to drainage or drought; xeriobole (J-qpta, dryness), a plant whose 

 seeds are scattered by dehiscence due to dryness; xerohyli'um (vXrj, 

 forest), a dry forest formation; xerohylad, a dry forest plant; xerophyll, 

 the leaf of a xerophyte; xerophyte, a dry soil plant; xerophyti'um, a 

 xerophytic formation; xerophilous, dwelling in a dry habitat; xero- 

 poi'um, a heath formation; xeropoad, a heath plant; xerosta'tic (o-raTiKo?, 

 standing), used of successions which are completed under xerophytic con- 

 ditions; xerotro'pic (xpoTrtKos, turning), applied to successions which be- 

 come xerophytic. 



zon \ion, that condition in which plant groups or formations appear in belts 



V zones. 

 ZD) j a belt of more or less uniform vegetation. 

 zo| lore {^S)ov, animal), a plant distributed by animals. 



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