320 GLOSSARY 
pagi'um (mdyos, rocky hill, glacier), a succession in a glacial soil; pagophy- 
ti’um, a foothill plant formation. 
pediophyti’‘um (zediov, plain), an upland plant formation. 
pelagi‘um (zédayos, surlace of the sea), a surface sea formation; pelagad, a 
plant of the sea surface. 
pelochthi’um (ayAds, mud, 69, bank), a mud bank form; pelogenous, pro- 
ducing clay; pelopsammic (ydupos, sand), composed of mixed clay and 
sand; pelopsammogenous, producing clay and sand. 
permobile, extremely mobile. 
perquadrat, a quadrat of 16 square meters or more. 
petasospore (zéracos, sunshade), a plant with parachute-like disseminules. 
petrium (rérpa, rock, stone), a rock formation; petrad, a rock plant; 
_petrochthi’um (69), bank), a rock bank formation. 
petrodi’um (zerpddys, abounding in boulders), a boulder field formation; pe= 
trodad, a plant of a boulder field. 
phelli‘um (@eAAev’s, stony ground), a rock field formation; phellad, a rock 
field plant. 
-philous (¢iAos), loving, dwelling in. 
=photic ($s, dwrés, light), pertaining to light; photoharmose, response to 
light stimuli; photometer, an instrument for measuring light. 
phreti’um (¢pyres, tank), a tank formation; phretad, a tank plant. 
phyad (¢v7, form of growth), a vegetation form, e. g., tree, shrub, etc. 
=phyll (#vAdor, leaf), combining term for leaf. 
=phyte (¢urdv, plant), combining term denoting plant; phyteris (épis, strife), 
plant competition; -phyti’um (d¢vreov, place covered with plants), com- 
bining term for formation; phytostrote, a species migrating by means of 
the plant body. 
pladobole (7Addos, moisture), a plant whose seeds are scattered by propulsion 
due to moisture. 
plasticity. the condition characterized by ready response to stimuli. 
pnoi’um (zvoy, blast), a succession in an aeolian soil. 
poi’um (7éa, meadow), meadow formation; poad, a meadow plant; poophyte, 
a meadow plant. 
polyan’thous (zoAvs, many, avos, flower), producing many flowers; poly= 
chro’nic (xpcvos, time), arising at two or more times; polyde’mic (Sqp0s, 
district), occurring in two or more formations or natural regions; poly- 
genesis (yéveors, origin), the origin of a new form at two or more places 
or times; polyphyle’sis (iAov, race), the origin of a form, species, or 
genus from two or more ancestral types; polyspermatous (o7épya, seed), 
producing many seeds in each flower; polyto’pic (rézos, place), arising 
at two or more distinct places, 
