Germplasm Resources Information Network (GRIN) Taxonomy Database
Acquired:
2003-01-21
Notes:
National Plant Germplasm System (NPGS), National Germplasm Resources Laboratory, Agricultural Research Service, USDA. http://www.ars-grin.gov/npgs/tax/index.html
Reference for:
Welwitschia
Source:
Gymnosperms of North America Update
Acquired:
2010-11-12
Notes:
Updated for ITIS by the Flora of North America Expertise Network, in connection with an update for USDA PLANTS (2007-2010)
Reference for:
Welwitschia
Source:
Tropicos, Aug. - Oct. 2010
Acquired:
2010-09-01
Notes:
TROPICOS, botanical information system at the Missouri Botanical Garden, available at http://www.tropicos.org/