have been cited consistently by later taxonomists as their 
major reason for retaining Brugmansia as a section or 
subgenus of Datura. The relative taxonomic value of 
these characters will be discussed below. 
After what appears to have been some initial uncer- 
tainty as to whether or not he should use Brugmansia or 
Datura in describing a new species in 1898, Lagerheim 
(12,13) in 1895 published a monograph of the Ecuadorean 
species of Brugmansia in which he left no doubt that he 
accepted Persoon’s view that the two genera were mor- 
phologically distinct. Although he made several mistakes 
in his identifications, Lagerheim’s work was the most 
complete study of the Brugmansias up to that time and 
was based on many years of field experience in Ecuador 
and Peru. 
In his monograph, Lagerheim also drew attention to 
the fact that Blume’s (6) use in 1828 of the name Brug- 
mansia for a new genus in the Rafflesiaceae was illegiti- 
mate, because Persoon’s genus in the Solanaceae enjoyed 
priority. Blume’s use of the name Brugmansia, how- 
ever, prompted van Zijp (20) in 1920 to propose the new 
generic name Pseudodatura for the solanaceous genus. 
This was done, apparently in ignorance of Lagerheim’s 
work, because van Zijp’s stated reason for proposing the 
new generic name was the long disuse and wide non- 
acceptance of Persoon’s name and its new use by Blume 
in the RafHlesiaceae. As was pointed out by van Steenis 
(19), long disuse or non-acceptance by some botanists 
does not invalidate a name. Van Steenis agreed with 
Persoon and Lagerheim that the character differences 
between Brugmansia and Datura justified a generic 
separation. 
More recent workers such as Safford (17), DeWolf 
(10), Barclay (2), Danert (9), and Bristol (7) have con- 
sidered the Brugmansias as part of Datura following the 
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