S. gnaphalioides, n. sp.

On S. humilis.

A monothalamous, small, solitary, oval or sometimes subspherical gall, ,23 — .55 inch long and .14 — .60 inch in diameter, almost always growing at the tip of a twig and without any side-shoots around it, very rarely from the side of a twig from a small side- shoot no longer than itself, sometimes porrect but oftener with the last inch or so of the twig on which it grows curved downwards, or angularly bent down- wards, or coiled 2 or 3 times round like the tendril of a vine. The leaves composing it are imbricate, sometimes more or less loosely appressed, (when it resembles somewhat the little lemon-yellow garden-flowers known as "everlastings" or ''immortelles" or the indigenous Gnaphalium polycephalum,) but more usually opened out towards their tips, and always with their extreme tips more or less pinched together so as to form a kind of beak and frequently reflexed. These leaves are all entire, sessile, pale green in the summer and in the autumn of a pale reddish brown or pale yellowish brown color with fine, appressed, whitish pubescence on their external surface, and they have a few in- distinct longitudinal veins but no normal midrib and side veins as in S. rhodoides. At the base of the gall they are small and orbicular, then larger and orbicular, then oval, then towards the tip of the gall elongate-oval and elongate-obovate, the tip of the leaf in each case taper-pointed in an angle of about 80° so as to form the beak before spoken of. In the inside they become linear- lanceolate and envelop the central cell as in the preceding species. Described from 72 specimens. Attains its full size by the end of July, and is quite common near Rock Island. Illinois. In two or three cases where the potato-like gall S. batatas n. sp. grew at the tip of a twig, I have noticed the gall S gnaphalioides growing sessile from near the tip of the other gall, evidently from one of the buds included in it. In November I have observed that many of these galls have the larva picked out of them, evidently by birds, and in February full I of them are thus emptied, the leaves of the gall being pecked off on one side. This does not occur with the allied galls S. brassicoides, S. strobiloides, and S. rhodoides, probably because the larva is there concealed and protected by a much thicker wall of leaves; but I have repeatedly in the winter noticed the same thing of the large, spongy gall of the Dipterous Trypeta solidaginis Fitch. Easily distinguished from its five allies by its much smaller size. From S. brassicoides it is also distinguished at once by its always being solitary; from S. strobiloides by the tips of the leaves that lie "to the weather" being not rounded but angulated and beaked; from S. strobiliscus by the tips of the leaves being generally opened out and recurved, and always beaked; and from S. rhodoides and S. coryloides by all the leaves being sessile, instead of the terminal leaves, and in the latter case almost all the leaves, having peduncles.

- BD Walsh: (1864) On the Insects, Coleopterous, Hymenopterous & Dipterous: Inhabiting the Galls of Certain Species of Willow. Pt 1st--Diptera^©

Reference: https://www.biodiversitylibrary.org/item/23810#page/603/mode/1up