Published in Journal of the Arnold Arboretum, in 1951, in volume 32, pages 1-26

Published in Journal of the Arnold Arboretum, in 1951, in volume 32, pages 27-58

Published in Journal of the Arnold Arboretum, in 1951, in volume 32, pages 82-97

Published in Journal of the Arnold Arboretum, in 1951, in volume 32, pages 99-122

Published in Journal of the Arnold Arboretum, in 1951, in volume 32, pages 139-150

Published in Journal of the Arnold Arboretum, in 1951, in volume 32, pages 201-225

Published in Journal of the Arnold Arboretum, in 1951, in volume 32, pages 344-368

Published in Journal of The Arnold Arboretum, in 1951, in volume 32, issue 1, pages 59-66

Published in Journal of The Arnold Arboretum, in 1951, in volume 32, issue 1, pages 67-72

Published in Journal of The Arnold Arboretum, in 1951, in volume 32, issue 1, pages 73-78

Published in Journal of The Arnold Arboretum, in 1951, in volume 32, issue 1, pages 79-81

Published in Journal of The Arnold Arboretum, in 1951, in volume 32, issue 1, pages 93-97

Published in Journal of The Arnold Arboretum, in 1951, in volume 32, issue 2, pages 123-138

Published in Journal of The Arnold Arboretum, in 1951, in volume 32, issue 3, pages 256-262

Published in Journal of The Arnold Arboretum, in 1951, in volume 32, issue 4, pages 390-402

Published in Journal of The Arnold Arboretum, in 1951, in volume 32, issue 4, pages 403-408

Published in Journal of The Arnold Arboretum, in 1951, in volume 32, issue 4, pages 412-414