This area is about the relationship between flower structure and pollination efficiency. It also includes reproductive costs and success. These studies are presented in chronological order with the most recent works listed first.

Records from a collection of  hybridizers around the world are also available in this area and are in chronological order.

2011 to Present

“The fertility of NNNX daffodil varieties,” by Theo Sanders, Germany, January, 2020

“Chromosome doubling of Narcissus varieties and species,” by Theo Sanders, Germany, December-2019

“The inheritance of the red and pink colour, the fertility of triploids, and the self-incompatibility of daffodils” – remarks to (1), Theo Sanders,  2017

“Crosses of tetraploid species with each other or with tetraploid standard daffodils,” Theo Sanders, Germany, February 2017

“Some Crosses with Diploid Tazettas and their Fertility,” Theo Sanders, Daffnet, June 2016

  Theo Sanders’ website with his findings about daffodil hybridizing, pollen and chromosomes

Narcissus cyclamineus crosses and their fertility,” Theo Sanders, February 2016

“The generation of fertile allotetraploid species hybrids by chromosome doubling ,” Theo Sanders, June 2015

Hybrids of different diploid narcissus species can be fertile by generating unreduced pollen 3; Theo Sanders, 2014

Pollen Volume Chromosome Content 3, Theo Sanders, 2014

“The Quest for Beautiful Green Daffodils,” Bob Spotts, Bulletin of the Horticultural Society of Canberra, 2013

Pollen Volume and Chromosome Content of Daffodils; Possibilities for hybridizing; update 2013, Theo Sanders

“Pollen Volume and Chromosome Content of Daffodils; Possibilities for hybridizing,” Theo Sanders; 2012

“Crosses of Standard Daffodils with Species,” Theo Sanders; Aug 2012, photos

“Crosses of Standard Daffodils with Species,” Theo Sanders; Aug 2012, Notes

Hybridizing Glossary, August 2011

1951 – 2010

  “Pollens Under Microscope“, by Shen Rui, a link to the Department of Chemical Engineering, University of Rochester, May 2006.

Brian Duncan Hybridising Records, 1964 – 2002

Bill Gould hybridizing records 1966 to 1971, and garden notes;   Handwritten, so not searchable.

Helen Link Hybridizing Records, 1963 – 1971

Helen Link Hybridizing Records, 1972 – 1979

Helen Link Hybridizing Records, 1980 – 1990

Helen Link Hybridizing Records, 1991 – 1996 plus notes

John Lea Hybridizing Records, 1948 – 1966

John Lea Hybridizing Records, 1967 – 1984

Looking at Pollen, Theo Sanders, The Daffodil Journal, Dec 2009

Hybridizers’ breakfast, ADS Convention, Columbus, Ohio, 1987

Hybridizers’ breakfast, ADS Convention, Memphis, Tennessee, 1986

Hybridizers’ breakfast, ADS Convention, King of Prussia, Pennsylvania, 1985

“From a Letter to David Willis,” Brian Duncan, [on breeding aims] The Daffodil Journal, June 1981

“Daffodil Propagation,” Peggy Macneale, Civic Garden Center Bulletin, May-June, 1978

“The Breeding of Pink Daffodils in Tasmania,” W. Jackson, RHS Yearbook 1959

“Some Favourites Amongst Daffodils I Have Raised,” Guy L. Wilson; Herbertia, Vol. 9, No. 1, 1953

“Thirty Years Breeding Daffodils,” Edwin C. Powell; “Narcissus Breeding Report,” W. R. Ballard; “Breeding Narcissus for Various Climatic Regions,” J.S. Cooley; Herbertia, Vol. 9, No. 1, 1953

 A collection of Roberta C. Watrous’ Hybridizing Records, 1944 to 1984

J. M. deNavarro’s Hybridizing Records, 1944 to 1972

1950 and Earlier

Richardson Hybridizing Records, 1928 – 1969

Oregon Bulb Farm Hybridizing Records from the 1920s through the 1960s

Narcissus Notes, “Waiting for the First Flower,” Roberta Watrous, The National Horticultural Magazine, Journal of The American Horticultural Society, April 1948

“Notes on Daffodil Breeding,” Guy L. Wilson, Herbertia, Vol. 13, 1946

“Commercial Breeding of Daffodils,” Frank Reinelt; Herbertia, Vol. 13, 1946

“Production of New Narcissus,” E.C. Powell; “A Few Narcissus Crosses,” C.W. Culpepper, Herbertia, Vol. 13, 1946

“Narcissus Breeding by an Amateur,” W.R. Ballard, Herbertia, Vol. 13, 1946

“Experiences in Breeding Narcissus,” J.S. Cooley, Herbertia, Vol. 13, 1946

“Steps in Producing Hybrid Narcissus,” Kenyon Reynolds, Herbertia 1944

“Bulbs from Seed,” David Griffiths, USDA Circular 311, June 1934

The Latest Hobby: How to Raise Daffodils from Seed; Cartwright & Goodwin, 1908