The gall's range is computed from the range of all hosts that the gall occurs on. In some cases we have evidence that the gall does not occur across the full range of the hosts and we will remove these places from the range. For undescribed species we will show the expected range based on hosts plus where the galls have been observed.
Up to the present time these three forms of galls have been considered as quite distinct species on account of their dissimilarity, two of them being smooth and the other more or less profusely covered with fleshy spines. But a careful study of the architects of these forms forces the conclusion that they are identical, there being no tangible characters by which to separate them. The spiny form of gall always grows upon trees with pubescent leaves, such as Hicoria tomentosa, while the smooth forms are always found upon trees with smooth leaves, such as Hicoria glabra, amara and probably other species.
Ph. c.-magna Shimer may also be considered as a variety of caryaecaulis. The form is found in Missouri growing on the petioles and bases of the leaflets of Hicoria amara. Some of the specimens also closely resemble those of subelliptica Shimer, which probably belongs to it, but of which I have not yet succeeded in obtaining the migratory form. On account of some slight differences in the gall, which are no doubt due to the specific differences of the infested trees, c.-magna may perhaps be allowed to remain under a variety name, though the architects in their different stages, as far as examined, show no differences by which to separate them from the typical caryaecaulis. The galls of this variety vary from 4-20 mm in size, the normal being about 10 mm. They occur on the under side of the petiole and the base and often the midrib of the leaves, and, when in the latter position, they generally project somewhat on the upper side. The shape varies from globular to sub-conical, or broadly ovoid. The surface is quite densely covered with a minute pubescence which gives it a slightly velvety appearance. The orifice beneath is rather small and transverse and tightly drawn together before maturity. Color greenish-white to yellowish-green beneath and beautifully crimson on the upper side. Usually single, though occasionally two or more may become confluent, with their cells, however, well separated.
