18 AMERICAN MIDLAND NATURALIST 
least when the other phases are blooming: leaves in general as 
long but only about half or little more than half as broad as those 
of the aquatic phases, always rough margined and scabrous on 
the veins and midrib: varying as to ochrea border according to 
the season as above; pubescent as in the preceding. Early in 
the season the whole surface of the leaf, upper as well as lower, 
as also the ochrea are sparingly hirsute with long white hairs: 
general shape of the leaves lanceolate to oblong, but the base usually 
subcordate, apex long acuminate: petioles 5-8 mm. long: inter- 
nodes about 2 cm. in length above and 3-6 cm. below where 
the older leaves have wilted: youns leaves dark purple on the lower 
surface. 
As far as I am able to learn this is the first report of discovery of 
the terrestrial phase and its varieties as connected with P. mesochora. 
Complete description of any one phase is quite difficult as plants 
may be found in which the lower leaves (developed in spring) 
are very hairy and the upper ones quite glabrous except on the 
margins and midrib. I have several times unearthed rootstocks 
having on one and the same plant all the different phases mentioned 
above, from the strictly aquatic or riparian forms to the most 
hairy terrestrial branches. Such specimens, owing to their length 
often 2 or 3 metres or more, are difficult to preserve. In spite of 
this wonderful variation of the different phases, P. mesochora is 
readily distinguished by constant characters of leaf shape, spike 
and ochrea from all the other aquatic or terrestrial forms of other 
amphibious Persicarias. Ochreae never have spreading borders 
in the blooming forms, thus distinguishing it easily from P. Hart- 
wright, as well as in shape of leaves and flowering spike. On the 
other hand P. jlwitans is readily distinguished in the aquatic phases 
by smaller foliage, leaf shape, and long wiry stems with slender 
leafstalks. The shape of-the leaves of the European P. amphibia 
as well as the spike are totally different, apart from the fact that 
the old world plant never had spreading herbaceous borders in 
any of the stages of its various phases. Besides that, the leaves 
of P. amphibia are mucronulate at the apex. 
Plants representing P. mesochora in my herbarium are Nos. 
263a, 263b, 263c.from St. Mary’s Lake, also 267a, 267b, 267¢ 
from St. Joseph’s Lake, Notre Dame, Ind., gathered in the summer 
of 1909. I have also found the plant in 1908 and 1909 in a deep 
ditch along the South Bend & Chicago Interurban Electric Line 
