WESTERN MEADOW RUE 291 
such a specimen never shows the foliage of the plant, and in all 
genera which, like this one, are of so high and complicated organ- 
izat on as to be compound-leaved, the leaves themselves are of 
the greatest importance to the systematist, as offering in untold 
thousands of instances the very best of specific characters. Now 
most of our tall meadow rues everywhere have their leaves so 
large that a single one taken from toward the base of the stem 
will fill an herbarium sheet as completely as its panicle of flowers 
will fill another; but nothing is so rare among our thousands of 
herbarium sheets as a good leaf of alarge thalictrum. So we have 
to deal with fragments; and the treatment of these plants in 
botanical manuals is also, and in consequence, always a failure. 
Not that ineompleteness of herba ium material is the sole cause 
of failure. The foliage when present has been strangely neglected. 
In untold instances in which a large genus displays in its extent 
great diversity as to outline, texture, coor, venation and indu- 
ment of its leaves, these are recognized as furnishing characters, 
often the very best, for species; but in thalictrum, now as of old, 
men strain their eyes in search for some small marks ‘of flower 
and fruit on which to establish species, and seem blind to the 
most pronounced differences among them in respect to leaves; 
this of course is partly due, though not wholly so. to the deficiency 
of pecimens in this particular. 
Whoever gathers,herbarium material of these large meadow 
rues should not stop short of five full sheets from each clump or 
colony. There should be (1) a panicle of the staminate plant 
in flower, (2) the same of the pistillate at*that stage, (3) a later 
gathering of a fruiting panicle in its full maturity (4) a perfect 
full-sized leaf from a pistillate plant, then (5) the same from a 
staminate one. In not a few species there is almost an extreme 
difference in outlice between the leaflets of the pistillate plant 
and the staminate. This a nouncement, which I believe is here 
for the first made, they who are determined that plant recognition 
and description shall be short and easy will pass in silence, and 
try to discredit it in whispers. It is at least the presentation of a 
new difficulty in the systematization of the species. Nevertheless, 
the difference is only one of outline, when it exists at all. The color, 
texture, venation and pubescence are the same in both sexes of 
the same species; so that this difficulty is not at all insuperable 
where the specimens are made in full, as above directed. 
