Published in Annals of the Missouri Botanical Garden, in 1973, in volume 60, pages 478-563

Created: 2010-01-08, modified: 2015-12-16

Published in Annals of the Missouri Botanical Garden, in 1972, in volume 59, pages 279-281

Created: 2010-01-08, modified: 2015-12-16

Published in Rhodora, in 1964, in volume 66, issue 765, pages 32-46

Created: 2014-06-16, modified: 2016-07-26