May 3i, 1924 Cell Sap Density and Environmental Conditions 
875 
Table IX .—Freezing point depressions and osmotic pressures of the sap of herba¬ 
ceous plants, including grasses and a moss on Big Cottonwood Canyon water¬ 
shed, classified by species, type, situation, altitude, and date of collection —Con. 
[Figures in italics represent averages of two or more determinations] 
Species and type 
Situation 
Alti¬ 
tude 
Date of 
collection 
Depres¬ 
sion of 
freezing 
point 
Os¬ 
motic 
pres¬ 
sure 
Stipa nelsonii Scribner 
Spruce-fir... 
Northern aspect, open_ 
Feet 
8,850 
1920 
Sept. 12 
Degrees 
C. 
1.33 
Atmos¬ 
pheres 
16.0 
Thalictrum fendleri Engelm. 
Aspen-fir__ 
Northern aspect _ 
7,450 
10,000 
8,950 
July 17 
July 15 
Sept. 9 
1.51 
18.2 
Spruce-fir___ 
Ridge-top_ 
l.*43 
17.2 
Do.... 
Eastern aspect, open_ 
1.41 
17.0 
Tithymalus robustus (Engelm.) Small 
(= Euphorbia robusta (Engelm.) Small) 
Chaparral.... 
Southern aspect_ 
7,500 
July 26 
1.56 
18.8 
Urtica gracilis Ait. 
Aspen-fir... 
Northern aspect_ 
7,450 
July 23 
0.88 
10.6 
Vagnera liliacea (Greene) Rydb. 
Aspen-fir___ 
Northern aspect.. 
7,450 
July 27 
0.98 
11.8 
Valeriana ceratophylla (Hook.) Piper 
Spruce-fir___ 
Northern aspect_ 
8,800 
July 25 
0.97 
11.7 
Veratrum speciosum Rydb. 
Spruce-fir_ 
Northern aspect___ 
8,800 
July 25 
0.97 
11.7 
Viguiera multiflora (Nutt.) Blake 
(=Oymnolomia multiflora (Nutt.) 
Benth. & Hook.) 
Chaparral.. 
Southern aspect.. 
7,500 
8,950 
Sept. 7 
Sept. 9 
1.57 
18.9 
Spruce-fir_____ 
Northern aspect.. 
1.02 
12.3 
Zauschneria garretti A. Nels. 
Chaparral. 
Southern aspect_ 
6,400 
Sept. 22 
1.16 
14.0 
Table X .—Summary of sap concentrations of all species by type, growth form, and 
season, Wasatch Mountain series 
Type and growth form. 
Season. 
Depression 
of freezing 
point. 
Osmotic 
pressure. 
Stream bank: 
Trees_____ 
Summer.. 
Degrees C. 
1.36 
Atmos¬ 
pheres 
16.4 
Shrubs_____ 
_do_ 
1.60 
19.2 
Moss....... 
.do.. 
0.22 
2.7 
Do...-. 
Autumn.... 
0.42 
5.1 
Sagebrush: 
Shrubs.. _______ ___ 
Summer__ 
2.51 
30.1 
Do__... ... 
Autumn. 
2.38 
28.6 
Do....... 
Winter__ 
2.75 
33.0 
Do....... 
Spring.... 
2.35 
28.2 
Juniper: 
Trees ....... 
Summer.. 
2.19 
26.3 
Do.....__.. 
Autumn... 
1. 32 
15.9 
Do_______ 
Winter__ 
2.26 
27.2 
Shrubs. .. .. .. 
Summer.. 
1.86 
22.4 
Do........ 
Autumn_ 
1.90 
22.8 
Western yellow pine: 
Trees __ _ _ . . 
Summer. ___ 
1. 85 
22.2 
Do .. .. 
Autumn_ 
1.45 
17.4 
Do.-. 
Winter_ 
1. 41 
17.0 
Shrubs. _ ...... 
Summer.. 
2.07 
24.9 
Do..... 
Autumn.. 
1. 68 
20.2 
