Chrysocoma subumbellata Thell. accepted as Chrysocoma longifolia DC. (original description)
Crepis hypochoeridea (DC.) Thell. (original description)
Crepis junodiana O.Hoffm. ex Thell. accepted as Crepis hypochoeridea (DC.) Thell. (original description)
Dicoma thyrsiflora (Klatt) Thell. accepted as Macledium zeyheri subsp. thyrsiflorum (Klatt) Netnou (original description)
Felicia erucifolia Thell. accepted as Aster erucifolius (Thell.) W.Lippert (original description)
Helichrysum aretioides Thell. accepted as Helichrysum sessilioides Hilliard (original description)
Helichrysum moeserianum Thell. (original description)
Lopholaena longipes (Harv.) Thell. (original description)
Lopholaena pauciflora Thell. accepted as Lopholaena dolichopappa (O.Hoffm.) S.Moore (original description)
Sonchus delagoensis Thell. accepted as Sonchus integrifolius Harv. (original description)
Sonchus scapiformis Thell. accepted as Lactuca tysonii (E.Phillips) C.Jeffrey (original description)
Ursinia bolusii Thell. accepted as Ursinia scariosa subsp. scariosa (Aiton) Poir. (original description)
Ursinia jacottetiana Thell. accepted as Ursinia montana subsp. montana DC. (original description)
Vernonia adulteriana Thell. (original description)