Notes
In this section many species have been described which differ only in slight characters and in my opinion several must be combined or deserve at most varietal rank. With the existing keys of Kukenthal, Ohwi, and Koyama identification appears often impossible. — (Noot.).
Citation
Mackenz. 1935 – In: N. Am. Fl.: 183
Nelmes 1951 – In: Reinwardtia: 371
Ohwi 1936 – In: Mem. Coll. Sc. Kyoto Imp. Un.: 339
Raym. 1959 – In: Mem. Jard. Bot. Montreal: 52, 60
