Mar. II, 1918 



Sterility in the Strawberry 



631 



Observations on the pollen condition in herbarium material of other 

 species than those above mentioned are not conclusive with regard to 

 the species examined because of the scarcity of material. Plants of 

 F. chiloensis from Sequin, Washington, from two localities in San 

 Francisco County, California, and from Bolivia, South America, pro- 

 duced perfect pollen. A single plant from Vark Hill, Cal., produced 

 small amounts of defective grains while two plants of a clone from Lake 

 Merced, Cal., which set fruit on the primary flowers of an otherwise 

 staminate cluster, produced in the neighborhood of 50 per cent of aborted 

 grains. A plant of F. chiloensis var. Scouleri, from Klantaak Island, 

 Yakutat Bay, Alaska, produced perfect pollen. F. platypetala from Mt. 

 Carleton, Wash., also produced perfect pollen. Although flowers of 

 comparatively few plants of these two species have been examined, the 

 facts seem to indicate that the pollen condition is much the same as that 

 found in F. virginiana and F. americana. 



POLLEN CONDITION IN CULTIVATED FORMS 



In contrast to the nearly normal pollen condition of the wild species 

 is the variable condition found in the cultivated forms in which practi- 

 cally all have a larger or smaller percentage of aborted grains. The 

 pollen conditions in varieties, controlled seedlings of varieties, and some 

 species-variety hybrids are given in Table VII. The percentages given 

 are based on an average of over 600 grains per count, and indicate fairly 

 accurately the pollen condition of the flowers studied. 



Table VII. — Percentage of aborted pollen in flowers, of various positions, from 120 

 cultivated varieties, l8 controlled seedlings of cultivated varieties, J3 selfed seedlings of 

 one of these, 3 F, plants of F. chiloensis X Wilson, 7 Fj plants of F. cuneifolia X 

 Magoon, and 10 Fg plants of F. vesca X F. cuneifolia. The percentages are based 

 on an average of over 600 grains per count 



Variety. 



Position of flower. 



Primary. 



Second- 

 ary. 



Tertiary. 



Position 



not 

 recorded. 



Cultivated: 

 Abington . . . 



Abundance . 



Amanda . 



Arizona . . . . 



Aroma 



Barrymore . 

 Beacon 



Bederwood. 



Bradley 



Brandywine . . . 



Brown Beauty. 



Charles 



Chesapeake . . . . 



26. 5 



63.0 



1-5 



13-6 



90.8 



37- o 



20. O 

 10.5 



33- o 



4.8 

 I. o 



97.0 



10. s 

 39- o 

 47.0 



