All the “Herbaceous Spireas” Worth Growing—w. E. Pendleton, “* 
THE TWENTY-FIRST OF THOSE HERETICAL ‘(LITTLE MONOGRAPHS” WHICH FIGHT THE IDEA THAT ALL PLANTS 
SHOULD BE INDISCRIMINATELY PRAISED AND NOTHING SAID ABOUT THEIR COMPARATIVE MERITS AND LIMITATIONS 
QO’ ALL the many plants that the people 
call spireas, the most refined are the 
herbaceous ones and by that same token 
we should expect them to be in the worst 
botanical muddle. Nor shall we be dis- 
appointed. All the stock troubles are here 
present in an acute form —few popular 
names, and those sadly mixed, all the 
scientific names changed from Spirea to 
something else; and when you calmly assume 
that the specific name is retained in the new 
genus, you find you are mistaken. 
But the whole thing is as clear as day, and 
every other botanical muddle could be 
made so, if botanists would only talk plain 
English to the people. I respect, as every- 
one does, the man who has formed the habit 
of confessing promptly his real ignorance of 
any subject, but I have no patience with 
mock modesty. There is nothing deadlier 
than such cant phrases as, “The roses are 
all mixed up”’; “I guess nobody knows any- 
thing about asters”; “There’s no use trying 
to classify German iris”; “All the distinc- 
tions have vanished in gladiolus”’; etc. 
For this is the easy way to “acquire merit” 
with people of general intelligence, just as 
the ignorant nursery laborer often fools 
the casual visitor into thinking he is learned 
because he can roll out the nursery names 
of plants. This form of pedantry is the 
analogue of apathy in politics. 
Any fair-minded person can see that 
Linneus ought never to have called these 
plants spireas in the first place. Everybody 
can tell the difference between them at sight, 
for the plants here pictured are all herbs 
with compound foliage, while the true 
spireas are shrubs with simple foliage. But, 
of course, vegetative characters are worthless 
for deciding whether plants should be put 
in one genus or another; the important things 
are the structure of flower and fruit. In 
this case we ought to put all the herbaceous 
“‘spireas” that have pyramidal clusters, into 
the genus Aruncus, because their staminate 
and pistillate flowers are borne on’ separate 
plants; and all those with flat-clustered flowers 
ought to go into the genus Ulmaria, because 
both perfect and imperfect flowers are borne 
upon the same plants. 
but shrubs in 
practically all the true spiréas have perfect 
flowers, i. e., no stamens:or-pistils lacking. 
The true goatsbeard (Aruncus sylvester) which is 
closely mimicked by the false goatsbeard (Astilbe 
decandra) 
Thus we get a perfectly clear and consistent 
scheme which the next generation can under- 
stand without trouble, and (whether the 
nurserymen like it or not), it is the system 
that is bound to prevail. 
We have two types of beauty in these so- 
called herbaceous spireas — the plumy 
and the flat-clustered. The most perfect 
example of the first type is the Easter pot 
plant that is the only thing the local florist 
This leaves nothing- 
the genus -Spirza and’ 
knows by the name of “‘spirea”’ (or else calls 
wrongly “Spirea Japonica”); the finest 
example of the second type is the hardy 
border plant called in books though hardly in 
‘real life the “dropwort,’’ and which every 
gardener knows as “Spirea Filipendula.” 
MIMICRY AMONG PLANTS 
But while there are only two types of 
beauty, there is a third genus to be reckoned 
with — Astilbe —and here enters what the 
botanist calls a “muddle” and I call one of 
the wonders of nature. For this Astilbe or 
“‘florist’s spirea” has a double, which gives 
‘us as beautiful an example of mimicry as 
the famous monarch and viceroy butterflies, 
For Astilbe Japonica (a member of the 
saxifrage family) is so closely mimicked by 
Aruncus astilboides (a member of the rose 
family), that the Japanese nurserymen 
sometimes send us both plants under the 
same name. And in our American woods 
another case of mimicry fools the school- 
boy, for the true goatsbeard (Aruncus 
sylvester) is mimicked by the false goats- 
beard (Astilbe decandra). 
There is nothing spectacular in this 
mimicry, for the only difference of impor- 
tance between the rose and saxifrage 
families is that the seed of the former 
rarely contains any albumen (or . endo- 
sperm), while in the saxifrage family the 
albumen is copious or fleshy. I admit 
that these examples of mimicry do not com- 
pare in interest with a “praying mantis” 
imitating a leaf, and I confess that I can- 
not explain why they exist, but are they any 
the less wonderful ? 
Consider how closely the florist’s spirea 
and its “double” resemble each other. They 
both have feathery plumes of small white 
flowers (panicled spikes). Remember that 
both inhabit the woods; are the same height 
(1% to 2 feet); bloom at the same time (June 
Tllustrating the two types of beauty in these ‘‘herbaceous spireas.’’ 
The plumy Astilbe Japonica on the left ; the fiat clustered Ulmaria Filipendula on the right 
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