The Underground Parts.—This tenacity of life and luxuriance of growth can be understood when the underground parts are examined. There are numerous irregular and often large tubers or enlargements which serve as the capacious storehouse of nourishment. They are often of fantastic shape. Various forms are shown in figure 1, plate 4. These occur at irregular intervals on the long and tortuous subterranean stems. It is said that they may be found several feet below the surface, though the eight specimens shown on the plate were found at a depth of six to twelve inches. If they all could be removed from the soil the weed would of course be practically annihilated. But when found at a depth of several feet—as seen sometimes in making excavations for foundations, walls, etc.—it is evident that the farmer will have to make extraordinary and long-continued efforts to destroy this pest. The less courageous may well be appalled in contemplating the herculean task. Fortunately swine are fond of the nutritious tubers, and voraciously devour them when they are given the freedom of the field and allowed to indulge in their natural propensities. Heavy coating of manure and winter plowing are also indicated.

Variations in the Leaves.—This form is easily recognized among the several species of Smilax indigenous to Ohio, though the leaves vary in size and shape to a remarkable degree. A large number of the common forms are shown in figure 2, plate 4. They are sometimes very broadly cordate-oval, wider than long; often ovate-cordate, oval or ovate, lance-oval, oblong to oblong-ovate, broadly to narrowly lanceolate and even linear; they are mostly cuspidate at the apex, in some cases tapering to acute or sub-acuminate. The base is mostly cordate and subcordate, but occasionally tapering. It is seldom that forms approaching halberd-shape occur in our region. An inspection of plate 4 will illustrate these several forms. The twig with fruit marked 6, bears a very common form of the leaf as does also the one marked 1. The broad-leaf form is not uncommon, but the very broad-leaf as seen in specimens marked 3 and 5 is of much less frequent occurrence. The very narrow leaves are as a rule borne on short stems—such as have developed in fields and meadows where the earlier stems have been destroyed or disturbed. But often on such stems (marked 1) the leaves are broad and have the natural shape.

Size of Leaves.—The size of the leaves is strikingly variable. The specimens shown on plate 4 being reproduced from photographs exhibit correctly this variability. Careful measurements also were made of leaves taken at random from hundreds selected to illustrate this point. These since they give both the length and width of the leaf demonstrate the shape as well as the size. The measurements are in decimeters and one hundred of them are as follows:

12×11.512.5×9.58.5×69×29.5×3.87.8×2.2
11×10.512×9.57.5×5.59×3.58×47.3×2.8
12×1112×118.6×5.48×1.57×2.86×1.7
13×10.611×11.88×66×0.78×3.85.3×1.6
11×1212.2×9.89×68×1.54.5×18×3.4
12.5×11.211.5×108.5×67×1.87×2.27.5×2.5
12.2×1013.5×10.58.5×5.86.8×27×3.26×2.5
12×1111.5×9.69.8×6.47.5×2.26.2×2.56×2.8
11×118×5.59×7.35.5×2.58.2×2.86×2.6
11.5×11.19×68.3×5.87.6×2.26.5×2.27×2.8
11×10.89.2×6.59×6.57.8×25.5×2.98.4×3
12×11.58×5.59.9×7.66.5×27.3×2.79.8×3.5
12×10.69×78.2×4.67×0.88×1.810×3.5
13×118.5×7.58.5×68.4×0.79.5×1.99.6×3.8
12×117.5×4.58.8×68×1.49.5×2.27.5×1.7
11.5×10.88.5×6.29.5×78.5×28.4×2.29.4×2.5
12×11.39×711.1×2.29×3.58×2.5

Description of the Leaf.—Neither the description as given originally (1787) by Walter nor those contained in our Manuals give any intimation of such variability as actually occurs. Some of them are as follows: Walter says “foliis oblongo-cordatis”; Wood, “ovate, finally nearly orbicular, abruptly contracted at one end”; Gray, “ovate, rarely subcordate, abruptly mucronate”; Britton, “ovate, acute or cuspidate at the apex, sometimes cordate at the base.” I would suggest the following as applicable to the Ohio specimens: Leaves mostly ovate, often broadly oval (occasionally broader than long), sometimes oblong-ovate, varying to lanceolate or even linear; the base mostly subcordate but often cordate or even cuneate; the apex cuspidate to acute or sub-acuminate.

Smilax spinulosa.—Britton and Brown in the illustrated Flora, 1:440, appends to the description of Smilax glauca the following paragraph: “Smilax spinulosa J. E. Smith, is a form with numerous small prickles on the lower part of the stem, and more elongated, sometimes halberd-shaped leaves. It occurs in southern New York, but is not well understood.” However Smilax spinulosa is given by these authors as a synonym of Smilax glauca, which according to my judgment is correct.

Plate 4.

Fig. 1.