co 
Cnicus muticus . . 
Prenanthes Serpentaria. . 
Helenium autumnale . 
Sericocarpus asteroides . 
Polymnia Canadensis ee 
Gnaphalium obtusifolium.. . . 
Senecio vulgaris . . oy 
Aster Nove-Anghe var. roseus 
Flieracium venosum . 
The general average is: 
Persistent HEIG- WEEUS 60 i. er se ee ee 
Wayside and fence row weeds 0. 60. . 3 33 
Netieecs Se ee 
This is direct evidence that the vitality of seeds of a species is 
a factor in determining the abundance of the plant and its ability 
to become a weed. 
OW 
— mt 
G6 OH NR wD 
TABLE SHOWING THE VITALITY OF SEEDs. 
= | a |ebe| 2B | & [48 | ay 
B | & 19 S| G2 iy (ee. | Be 
SPECIES STUDIED. le Oe | ee ee ee 
eg a3.| $e | 28 |eoa| 2s 
2 a oad gs 2a 0.0 os 
So | Gt RRR Se ee tee ee 
Go eee ee ee te ee 
Aster Nova-Angue ........4. 50 30 I 3 4 8 5 
frenanthes Serpentaria,.....\ 50 40 9 5 14 28 15 
Eupatorium perfoliatum...... 50 29 6 6 12 24 16 
Ambrosia Wifae ..c.. sekcaak 50 63 13 13 26 52 23 
Gnuaphalium obtusifolium..... 50 15 I fe) I 2 I 
dmula Helenium ok 50 15 21 24 45 90 7oO 
Polymnia Canadensis,....... 50 ° I o I 2 2 
Mrtteh LO oo. ee 50 ° 19 20 39 78 78 
Solidago Serotinag,......e00.- 50 Est. 7 13 20 40 I 
Coreopsis discoided........... 50 28 9 16 25 5° 32 
Semecio Vulgaris... ...c..0005- 50 5 a. ° oO ° ° 
fleliopsis helianthoides........ 50 15 20 22 42 84 65 
Sericocarpus asteroides,...,.. 50 | 128 2 4 14 4 
Helenium autumnale..... ven} §0 70 8 8 16 32 13 
Hieracium venosum.... 2... 50 14 oO. fe} ° ° fe} 
Taraxacum officinale,....... 50 8 3. 8 Il 22 19 
CtCMS MUN CHE iG cs ee 50 8 at 8 19 38 53 
DOUG PE oe. cerca cs 50 3 10 19 29 38 53 
Aster Nove-Anglie var. roseus,| 50 | Est. 7 9 16 32 I 
Descriptions of Akenes and Seedlings. 
Eupatorium perfolatum, L. (Plate CXXXIV. A-D.) “Akene — 
5-angled destitute of intervening ribs.” The outer wall min-— 
utely perforated, 2 mm. long, black, pappus as long as the akene, _ 
