246 AMERICAN MIDLAND NATURALIST 
The plant was hitherto known in the aquatic and subaquatic 
phases. 
4. Persicaria carictorum Nwd. Aquatic and Terrestrial, also 
early summer sterile terrestrial. 
5. Persicarta coccinea Muhl. Riparian phase. (Known 
hitherto in the terrestrial and aquatic.) 
6. Persicaria ammoplila Greene. Aquatic and riparian 
phases. 
7. Perswaria nebrascensts Greene. Subaquatic or riparian. 
phase. 
8. Perstcaria pratincola Greene. Vestigial aquatic and 
riparian phases. 
9. Persicaria oregana Greene. ‘Terrestrial phases. tf 
to. Persicaria rigidula (Sheldon) Greene. Terrestrial phase 
also riparian. 
CONCLUSIONS. 
1. The admission of P. emersa as commonly understood by 
botanists, to specific rank on the basis of the “specific” distine- 
tions outlined in our manuals and floras is illogical for those that 
reduce P. Hartwrighttt as unworthy of specific rank. Those who 
suppress one must consistently and for quite similar reasons refuse 
to accept the other. 
2. There is no logical alternative between accepting the 
Linnaean view of one sole species of amphibious Smartweed on 
the one hand, and Dr. Greene’s view of a number of valid distinct 
species on the other. 
3. On the basis of distinctive specific characters analogously 
used for well recognized species considered valid in other groups, 
the method of Dr. Greene is the most logical of all the methods 
referred to. 
4. All the different species of amphibious Persicarias have, 
potentially at least, two or several phases, though one ot other 
may be vestigial or perhaps absent. e.g. P. fluitans, (as far as we 
know. ) 
5. Polymorphic plants in order to be easily and distinctively 
recognized in every phase, must be described in our manuals 
separately for each phase. 
6. The system of distinctions as outlined in our manuals 
of to-day fails to distinguish even the species which they actually 
recognize by characters which are specifically differential. Other 
