Oct., 1921] BECHTEL — FLORAL ANATOMY OF URTICALES 
Ulmus ftdva Michx. is described as having perianth lobes and stamens 
ranging from 9 to 5. However, among the many flowers inspected by the 
writer, 8 was found to be the highest number and 5 the lowest, with one 
instance of the latter. The common number is 7 or 6, while in U. americana 
it is 8 or 7. The perianth of U. fulva is more prominently lobed than that 
of U. americana, but zygomorphy is as conspicuous. The traces to the 
floral organs pass off from the stele in close succession, but the traces to the 
stamens pass off higher up and later than do those to the perianth (PL 
XVII, fig. I, U. fulva has abortive bundles similar to those of U. 
americana, alternating with the perianth and stamen strands. However, 
in this species these abortive bundles exist as a distinct whorl and not 
merely in the anterior part of the flower as in U. americana. These are 
organized tissues in the form of strands (PI. XVII, fig. 2, d; fig. i, d), but 
they possess no appreciable lignification. They persist to a level where the 
strands to the stamens are definitely isolated. The flower figured shows the 
anterior-lateral stamen suppressed, but its abortive trace (PI. XVII, fig. 2, 
s^) can be followed for 30 microns. The vascular supply to the carpels is 
the same as that of U. americana. 
Ulmus racemosa Thomas is described as having the perianth lobes and 
stamens ranging from 8 to 5. All the flowers studied, from one tree only, 
had perianth lobes 8 to 7 and stamens 8 to 6. The flower tends to be 
zygomorphic to the same degree as that of U. americana. Traces into the 
floral organs originate and pass off in the same sequence (PI. XVII, fig. 3, h; 
fig. 4). The presence of abortive bundles alternating with the bundles to 
the stamens and appearing later and above them was limited in this species 
to one instance (PI. XVII, fig. 3, d, d^). Here only two such bundles were 
found. 
Ulmus campestris L. is described as having the perianth lobes and 
stamens varying from 5 to 3. In flowers from two trees, the perianth lobes 
were found to range from 6 to 4, and the stamens from 5 to 4; six lobes in 
the perianth are rare, and the common relationship is 5 to 4, or 4 to 4. 
The perianth cut away from the flower and studied under a microscope 
reveals the fact that the lobes are not the single structures that an observer 
takes them to be when inspecting the flower macroscopically. The hairy 
margin of the lobes obscures very small lobes on their sides (PI. XVII, figs. 
6, 7, a, h). In figures 6 and 7, the lobes 2 and 4 are anterior and posterior 
respectively; lobes i and 3 are lateral. Such is the origin and appearance, 
however, of these lateral veins a and h, that they should not be looked upon 
as branches of the midvein, but rather as veins separating from the vein 
leading to the main lobe. That is, veins a, i, and h in figures 6 and 7 are 
the continuation of the traces, which pass out of the stele contiguously and 
remain in conjunction for a short distance, separating early. These bundles 
from their behavior (PI. XVII, figs. 6, 7, a, i, and h) may be considered 
alternating parts of two perianth whorls, which through reduction have 
