JSTOR:
Dr. Lowry of Missouri Botanical Garden speaking at the 2010 AETFAT Congress in Antananarivo, Madagascar
JSTOR:
Pelargonium lobatum Willd. α. sphondylifolium published illustration from Curtis's Botanical Magazine
JSTOR:
Arctopus foliis superne spinis stelliformibus echinatis, laciniatis, & in cilia diductis; floribus umbellatis, from South Africa Rariorum Africanum Planatarum, Burmann
JSTOR:
Letter from David Livingstone to Sir William Jackson Hooker; from River Shire, Malawi; 1863