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    Wind Cave

    National Park South Dakota

Seed Study - Helianthus annuus

Helianthus annuus - Annual Sunflower

Helianthus annuus - Annual Sunflower

NPS Photo

Species: Helianthus annuus
Common name: annual sunflower

Seedling Identification: Fairly large rounded cotyledons with large, pubescent true leaves.

 

Helianthus annuus – common sunflower
Average number of good seeds per gram bulk matter: 74
Average number of good seeds per gram cleaned: 1667
Commercial estimates of seeds per gram: n.a.
Percent seed: n.m.
Percent live: 62
Collection dates: September 9 and 15
Collection effort: 29 grams in 6 person hours.
Collection notes: Easy to collect if large amounts can be found. Seed tend to be damaged by insects so collect more than you think you will need.
Cleaning notes: Bulk seed measurement was off the receptacle (disk) but with lots of bracts. Cleaned seed was hard seeds only.

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