1920] Mackenzie,—Purple-flowered Eupatoriums 161 
He is led to do this because in the second edition of the Species Plant- 
arum (p. 1173) Linnaeus gave a partially new description of Eupa- 
torium purpureum, the changes self-evidently being based on a speci- 
men of Species No. 4. It is to be noted that certain phrases quoted 
by Prof. Wiegand from the description in the second edition as being 
particularly applicable to Species No. 3, are in truth copied from the 
description in the first edition and are based on Species No. 1. 
But to me it seems absolutely immaterial what Linnaeus did after 
he published his species. It seems to me that we can identify the 
plant which he had before him and on which his own description was 
based. "This being the case we are not justified in disregarding his 
description and resorting to the works of the earlier botanists to 
determine the application of his name, merely because in a later work 
he confused the first plant studied by him with another. As I see it 
the type, as we now call it, of Eupatorium purpureum was the plant 
from which he drew his own description, quite probably the Hortus 
Cliffortianus plant; and it is this plant to which the name should 
be applied. This plant is the Species No. 1 of this paper, and is the 
plant commonly identified in botanical manuals as Eupatorium macu- 
latum. It is illustrated as such in Addisonia (pl. 132). 
EUPATORIUM MACULATUM L. 
Let us next consider the above species. "The original description 
(Amoen. Acad. 4: 288. 1755) is as follows: 
“76. EUPATORIUM (maculatum) foliis quinis tomentosis lanceo- 
latis aequaliter serratis petiolatis venosis. 
“ Eupatorium folis lanceolato-ovatis serratis petiolatis, caule 
erecto. Hort. cliff. 396. 
“Eupatorium novae angliae, urticae foliis, floribus purpurascen- 
tibus, caule maculato. Herm. parad. 158. t. 158. Moris. hist. 3. p. 
97. 5. 7.1. 18. f. 3. Raj. suppl. 187. 
“ Habitat in America septentrionali. XY 
“Descr. Folia quinque vel sex ad genicula, lanceolata, aequaliter 
serrata. Caulis tenuissime maculatus. Varietas Eupatorii pur- 
purpurei ad hoc, ut & ejus synonyma & descriptio spectant. Eupa- 
torium enim purpureum foliis quaternis, lanceolato-ovatis, inaequal- 
iter serratis, rugosis est." 
The above is certainly a very sad mixture. Linnaeus is evidently 
attempting to remove from Eupatorium purpureum the plant with 
equally serrate, veiny, lanceolate leaves occuring in 5's or 6's at the 
