ON TUE ENGLISH MINTS. 235 
the shortness of tlic stamens, when oecurriag, is compensated by a 
superaLuiidant development of roots^ ray observations do not enable 
me positively to say. 
As regards the classification of the forms, it has been usual amongst 
modern authors to separate them, according to the position of the 
flowers into a Spicate, Capitate, and Verticillate group. The objection 
to this is that we have plants which barely differ from one another 
except by this very characteristic. Mentha Idmita or aquatlca, as 
defined by Smith and Fries, includes spicate, capitate, and verticillate 
forms, and from one end of the series to the other the change is very 
gradual. Mentha pij)e?Hta, too, normally spicate, becomes capitate in 
some of its forms. Fries makes Sessilifolice and Petlolatce his primary 
groups, but both M. sylvestrk and viridis have occasionally short stalks 
to the lower leaves, whilst on the other hand M. crispa, E. B., S. 2785, 
w^hich all agree to refer as a monstrosity either to piperita or kirsuta^ 
has sessile leaves ; and in the verticillate Mentha, the transition from 
the very nearly sessile-leaved M, cardiaca cf Gerarde, through M. gra- 
cilis and pratensis to the fully-stalked species, is as gradual as possible. 
Dr. Wirt gen forms his groups upon the circumstance of whether the 
corolla-tube be naked or hairy internally, and the seeds smooth or rough, 
and treats a large number of the forms as hybrids. By this method also 
plants, otherwise very closely allied, are placed in diiFerent divisions. 
As regards hybridity, so far as I have had the opportunity of observing, 
for instance, the forms which range under M, mtlva^ Smith, they are 
neither usually associated, growing in small quantity, with M, Mrsuia 
and arvensis growing together in large quantity, nor less liable than 
the other Mints to perfect seed. I will therefore use the ordinary 
arrangement, and enumerate all the English forms which I have ex- 
amined, quoting the synonyms of Sole, Smith, Boreau,* and Wirtgeqf 
regularly, and a few others occasionally. 
Group 1. Mentha spicate. — Whorh offotcers oggiomerated into 
cylindrical or oUong terminal spikes. 
SessiliJbHcE. 
I. M, rolundifoUa, Linn., Smith ; Boreau, 1910 ; Wirtgen, nn, 7, 8. 
M, sglvestris^ Sole, t. 3. 
Stem 2-3 feet high, erect, hardly at all branched below, firm, 
* Flore du Centre de la France.' Third edition. Paris, 1857. 
t ' Herbarium Mentharum Ehenanarum/ Third edition. Coblenfcz, 1865. 
R 2 
