1322 PHYSIANTHUS 



S scales attached to tlie miiUllpof the tube or Inwer. flat 



seeds long, bearded. SchulHiiia and rijv<iaiiilin~ -li.nild 

 perhaps be considered as siiliL-rn. la. tli. ii.nn. i , -,,111:1111- 

 ing the hairy plants with Muu.uliai tuim,! ^ii:,|„,i ils.; 

 the latter nearly glabrous plants wiili ^(llli(■^vh:lt -.mIvct- 

 shaped fls. 



A. Fls. 2-3% in. across, umbellate. 



Aratijia gravfiolens, Masters {Phijsidnthiis graviolens, 

 H<irt. P. iiiirlriimiis, R. Grab. SchubMia graveolens, 

 Liiiiil. ,s'. '/>■" uili flora. Mart.). Densely covered with 

 liMi-.h, -|.r, :,,!,, I- yellow hairs: Ivs. 3^^ x 2-2% in., 

 <iti,.\ ai,,, a,-iiitiitiare, greatly narrowed and cordate at the 

 lia-;.'. liairv c.n lioth sides: fls. funnel-shaped, i. e., 

 swelled at the throat. S.Brazil. B.M. 3891. B.B.32:21. 

 U.F. 3:3U9. 0.0.111.4:271. Gn. 32:007. A.G. 13:695. 

 AA. Fls. 1 In. across, cymose. 



Arailjia sericnfera, Br.'t I \ . ■!n„;,s. G. Bon. A. seri- 



■ I'"' 1^' • I,.,,, .'ri-rt, Mottet. Physi- 



'1 -■ ai,n,us: Ivs. 3xlJiin., 



"' ,' M' at the base, minutely 



IM.I,,-^,', ni i„(,,',A , !!-, -,,:.,, , ^:,:,|„,,l. i. e.. iKit swelled at 

 the thr.iat, pale m^.- in tin- l,n,l and .,„lv faint U- ...Inrnlis. 

 S.Brazil. B.M. .-i-Jiil. 1'.. li. Jl : I 7,-,|i. 1 ,1 . H I. J :i;-,:!; 

 20:523. R.H. IK.'.T, [,. s:i; l.s.s:;, ,,. |,^^. i.n. Ji, ,,. Mil); 

 34, p. 397. Mn. (i, p. _■»(;. -Tlir plant .-,, al...v.- .l.-s.-rila-d 

 is the Physiantluis albeiis or Araujia iilbeiis of the 

 t^fle- G. W. Oliver and W. M. 



PHYSIC NUT, FRENCH. Jatropha Curcas. 



PHYSIOLOGY OF PLANTS. What Plant Physiology 

 M< 'I Hs. — 'Vhi' vi-ry fat-t of cultivating plants presup- 

 pos.-s sonn- km. win, i^'.- of how the plant lives, i. e., of 

 plant piiysioloi;y. Tin- jiristine cultivator sought to 

 imitate nature, and by a .system of selection and in 

 favoring by cultivation the few plants which seemed 

 best suited to his wants, he really improved and devel- 

 oped what he demanded for 

 use. Thus with but little 

 knowledge of how the plant 

 lives, improvement in definite 

 directions has gone forward 

 from thr- r-arli,--;t times. Never- 

 tln-l,---.. tin- limitations in im- 

 l.i-n\ .-nn-Mt lia\-.- licen regu- 

 late-,! iail,,-r l.v limitations in 

 lluul•-^ kuowlndge of plant-life 

 than by any lack of capacity 

 for development in the plant 

 itself. Every new discovery 

 in plant physiology must 

 oveiitiially be of value to the 

 liorticulturist in one way or 

 another, and the fundamentals 

 of physiology are of prime im- 



,V study of plant-life in field 

 d f,Mrden alone would hardly 

 vr iriven foundation for 

 ,nt ,,i,v--i"IoL'v as a science. 



Ill I ' , -1l-.- of the inti- 



f the plant 



■ I method must 

 ■ l-i- i-,l l,-,ih ill the field 



In- III -afiry. Neither 



■ pr -sses can be 





the 



sn|.aral,- ac'iivitii-s are in some 

 way isolated and each for it- 

 self investigated by a study 

 1777. of cause and effect. From the 



Root system of squash germination of the seed, and 

 plantlet showine adher- tin- iiitrrrstin;,' rlianges which 

 ence of soil particles. this inv.,l\ns, through all of 



tin- iiiii-i.-at,- livini; processes 

 of breathing, taking in of In,,, I. di^, xti,,n and assimila- 

 tion of food material, and tin- l',n-mati,.n of new plant 

 substance, we have the plant living, the plant in ac- 

 tion. Similarly, as a sensitive organism, it is to be 

 studied as acted tipon by all of the external conditions 

 about it, and as responsive to every change of environ- 



PHYSIOLOGY 



ment. In the broader sense of the term, physiology is a 

 study of this living, sensitive, adaptable, reproductive 

 plant. 



Every living process and every change produced by 

 season or other condition has its charm and interest if 

 the underlying principles are understood. A knowledge 



tliese bro.adens the sympathies for the general ob- 

 rver of plants and gives the reflective cultivator a 

 ler appreciation of the buoyant living organism with 



Thr F II iirli <.-,,■: nf n,:i.i-„.'j Differ. — Root, stem, leaf 

 d tlnwrr ar- ,| i--, r :. lis or parts of the common 

 lti\at,-,l ]-ii I - I liiiet organs each of these 



s di-linii, I ,. . 111,-tions, more or less pecu- 



phyt 



-h,. s,,ii, i.oL'. water, or epi- 

 - I-, --nil, rill, -s and modifica- 

 II -- -i-- I-, si tin, slightly 



differing functions wh , i ill,, I n|„,n to per- 



form. In the same wiiv ilni, ai, \ iirniiions in the re- 

 quirements of leaf, stem and otlu-r jiarts commensurate 

 with the conditions of growth and the functions of the 

 parts in their relations to external conditions. 



Desert vegetation consists generally of very curiously 

 modified plants. There are, in goin-ial, ., -i ,1- iT:,'i> 

 thickened and reduced green stems. Man ' 1' 



may store up large quantities of food n 1 

 and in some a large sujiply of water m. i- 11, n. 



.i,rdiiiati-d to function. 



l>o„.~Even the plant of 



I <h-p(-iident organism as 



1 would imply. It lives, 



In every living process 



its hu-k of grm-ral 1.. 

 moves and \\oi-ks i-\-, 

 work is acc<pinidislH-d 

 the rigidity of its strn 



internal processes of ;, m ■- 'i-'.wtl,, and d'-\-*-l- 



opraent. The forciiii; 01 1 r -u-h tin s,.ii and 



rock, and the resistai 1 >\ imK .-md oiln-r 



agencies are examples ,,r il,,- ,11, ri.-y ,lai!y exiM-mled in 

 maintaining itself. In onler to aoeomplish this work, 

 oxygen is necessary, as with the animal, the energy be- 

 ing secured from the breaking down of organic com- 

 pounds. Ordinarily, the leaf and st.-m are bathed in 

 the a I -1-1 1, r, , ai,,'] -,, lli,- - 1, |--Tri-- i,,l |-r,--, 11,-e of oxy- 



ox> :;- -I I ■ 1.1 ■■ ,. I. !--■ II, -<1 Stom- 



ates, ,,i -I - 1 1 , -,-,-, III I 111 ■- '11 may also 



seciin- a Ini il,, 1 , ■! 1 1, - -. 1 1 1 - 1 n , 1 ii-ushions 



known as it-Ill I - 1 -' '- mi 11 1 .walnut, 



elder, etc. I;- n 1 . iilvofoxy- 



gen, and tt 1 1 - 1 1 .1 - 1 ._ 1 lis- if de- 



prived of it for -hi.,11 p' 11-1,1- ,_,! iiiii,_-. A 11, |, I of Indian 

 corn flooded with water will soon present a very un- 

 healthy appearance, on account of the fact that water 

 forces the air out of the soil. Cultivation is in part 

 a means of aerating the roots. Many greenhouse difli- 



