The Outlawed Spireas and Their Kin—By W. E. Pendleton, 
Connec- 
ticut 
WHY THE BOTANISTS HAVE THROWN OUT OF THE GENUS SPIRZA ALL THE HERBACEOUS SPECIES 
AND MANY OF THE MOST BEAUTIFUL SHRUBBY ONES—THE KINDS EVERYONE SHOULD KNOW 
The twentieth of those heretical “ Little Monographs” which try to find out the comparative merits and limitations of plants instead of passing out the dry bones of botany and 
whose chief indiscretion is that they tell what everybody thinks and talks and wants to know but no one dares set down in print. 
ie IS the irony of Fate,” say the old gar- 
deners, “‘that as soon as a genus becomes 
known to everybody for the many lovely 
Species it contains, the botanists get their 
little hatchets and cut out of that genus nearly 
all the species that everybody loves the most. 
And it seems as if the learned took particular 
delight in inventing for these outlaws just 
the hardest names they can think of.” 
However that may be, I would rather 
have in my garden the dozen botanical exiles 
Iam about to mention than any of the kinds 
The ash-leaved spireas or sorbarias differ from 
the true spireas in having compound foliage and 
fluffy pyramids of bloom, often a foot high 
that I described last month in “All the 
Summer Spireas Worth Growing.” I must 
confess, though, that I believe the botanists 
have done the right thing in excluding these 
plants from the genus Spirea and I hope I 
can show you a good part of the evidence 
on which this judgment is based. 
ASH-LEAVED SPIREAS OR SORBARIAS 
Surely we have no such glorious flower- 
cluster among the true spireas as in the 
ashleaved spireas. The great defect of the 
conical-clustered spireas is that their clusters 
are so dense as to be stiff, and even the best 
of them are only eight inches high. In the 
sorbarias we get the same type of beauty 
liberated and glorified, for all of them have 
great, fluffy, white pyramids that are full of 
grace, and in some species these clusters are 
twelve inches long. ‘To catch the spirit of 
this group you have only to look at the 
picture on the following page and imagine 
these clusters to be a foot high. 
Moreover, the foliage of these sorbarias 
is as unforgettable as it is dignified, for the 
leaves look like those of the mountain ash. 
Indeed, the name Sorbaria loses its terrors 
when you know that it means “resembling 
the mountain ash.” None of the true 
spireas has a compound leaf; they all have 
simple, non-committal foliage—a merely 
““leaf-shaped” sort of leaf. 
A beginner might think that this com- 
pound foliage would be sufficient reason for 
throwing these sorbarias out of a genus hav- 
ing simple foliage, but the important char- 
acters that determine genera are the struc- 
ture of the flower and fruit. In Sorbaria the 
five pistils are opposite the sepals, while in 
Spirea they are opposite the petals or else 
less than five in number. This may seem a 
small distinction to a gardener, simply be- 
cause he is not used to studying the structure 
of small flowers, but it is a character that 
will separate into two groups the fourteen 
genera comprising the spirea tribe of the 
rose family. 
The sorbarias belong to the unkillable 
class of shrubs along with mock orange, lilac, 
and other fast-growing ravenous creatures, 
but they have the “defects of their virtues.” 
Anybody can grow them, but you must see 
that they do not spread too fast by suckers 
and crowd out choicer things. Also the 
flower clusters get unsightly when passing 
and had better be cut off then, but this is 
true of all spireas and of many other shrubs. 
If the name “ash-leaved spirea” were 
restricted to any one sorbaria, that species 
should be SS. sorbijolia, because it is the 
most popular. It is native to Asia but has 
escaped from cultivation a little in this 
country. The individual flowers are only a 
third of an inch across, but the clusters are 
often a foot long. 
There is a “large-flowered” species (S. 
grandiflora), but the flowers are only an 
inch across and the clusters are only five 
inches long. 
Both the above species have the ramifica- 
tions of the flower cluster pointing upward, 
while in the next two they are spreading. 
The Himalayan sorbaria (S. Lindleyana) 
was thought to be the best available species 
of this type, until the Afghanistan sorbaria 
(S. Aitchtsont) was discovered. Both have 
foot-long clusters, but the latter species is 
hardier. One can tell it by the red color of 
335 
the young branches, those of the tender kind 
being green. 
There is a rare sorbaria that has the 
great interest of having twice-pinnate foliage 
and flowers half an inch across, but the 
clusters are only five inches long; and unlike 
the other species, it prefers a rather dry soil, 
full sunshine, and perfect drainage in winter. 
With these precautions S. Millefolium is 
hardy in Massachusetts, though native to the 
southwestern deserts. 
The first two and the last-named sorbarias 
bloom in June or July, the others about a 
month later. S. sorbijolia attains a height of 
five feet, grandiflora only three, the others 
six or more. 
LARGEST DROOPING CLUSTER— SCHIZONOTUS 
Even more refined than the flower cluster of 
Sorbaria is that of the white beam-leaved 
spirea (Schizonotus discolor), because it is 
not erect but gracefully drooping. The 
drooping character is not shown in the accom- 
panying photograph, since it is caused by 
the arching of the branches. ‘The clusters, 
however, are not quite so long (about ten 
inches) and the foliage is not particularly 
interesting. It blooms in July and averages 
about five feet, but has been known to attain 
ten and even twenty feet. Such a bush, when 
covered with flowers, must be a noble sight. 
The beam-leaved spirea grows wild all 
the way from Oregon to Guatemala and as 
The white beam-leaved spireas (Sc/izonolus S- 
color var. ariefolia, known to nurserymen as Spi7'ee 
ariefolia). Clusters nodding, ten inches long 
