Geological Survey Bulletin 204 Fossil Flora of the John Day Basin, Oregon

Family HYDRANGEACEÆ.

HYDRANGRA BENDIREI (Ward) Knowlton.

Pl. IX, figs. 6, 7.

HYDRANGRA BENDIREI (Ward) Knowlton in Merriam, Univ. Cal., Bull. Dept. Geol., Vol. II, No. 9, p. 309, 1901.

Marsilea Bendirei Ward, Fifth Ann. Rept. U. S. Geol. Surv., p. 446, 1885.

Porana Bendirei (Ward) Lesquereux, Proc. U. S. Nat. Mus., Vol. XI, p. 16, Pl. VIII, fig. 4, 1888.

Sterile flowers of large size; calyx lobes of firm texture, broadly obovate, oval, or nearly circular in shape, considerably overlapping, obtuse and rounded at apex, truncate or slightly narrowed at the sessile base; nervation strong, consisting of some six or eight nerves of equal strength, the central one passing apparently to the tip of the calyx lobes and having two or three branches at various distances which anastomose with it some distance below the apex; other nerves diverging and joining by broad loops with several series of smaller loops outside; nervilles producing quite large irregularly quadrangular areas in which there are often free veins.

Four more or less perfect examples of this exceedingly interesting species have been found. The original specimen is nearly 4 cm. by 3 cm. in size, the large sepals being 2 cm. long and 1.5 cm. broad. The next discovered specimen was obtained by Dr. John C. Merriam in 1900. It is not quite perfect, but has the nervation very well preserved. The sepals are about 2 cm. long and nearly as broad. The two remaining examples were obtained by myself in 1901.

The original specimen, as may be noted under the synonymy, was first tentatively referred to Marsilea, and was later placed under Porana by Lesquereux, who correctly recognized its nature. Lesquereux, however, was in error in supposing that the sepals were "connate to above the middle." They are undoubtedly free and overlapping, as shown by the present drawing. (See Pl. IX, fig. 6.) The example secured by Dr. Merriam is, as already stated, not perfectly preserved, but as nearly as can be made out, it consists of only three sepals, although the fourth may be present, concealed under the others. They are clearly free, however.

The fossil forms referred to Porana consist of the more or less leathery sepals and are usually five in number. Two species have been described from the United States by Lesquereux, both coming from Florissant, Colorado. Porana Speirii a is a five-lobed connate species, while P. tenuis b has never been figured, but is described as having the sepals separate to the base. The first is very distinct from the form under consideration, while the latter can not be well compared.

On first examining these specimens, especially the one collected by Dr. Merriam (Pl. IX, fig. 7), they seem to be referable to a Cornus of the type of C. florida or C. Nuttallii Aud., but the absence of any marked indication of the flowers in the center apparently precludes their reference to this genus.

At the suggestion of Mr. Charles Louis Pollard, of the United States National Herbarium, these fossils were compared with various species of the genus Hydrangea, and the resemblance between them and the sterile flowers so characteristic of this genus was so striking that they have been referred to Hydrangea.

Eight fossil species of Hydrangea have been described from the European Tertiary, but none of them approach closely to our form.

Locality.—Van Horn's ranch, South Fork of John Day River, 12 miles west of Mount Vernon, Grant County, Oregon. Collected by Maj. Charles E. Bendire (U. S. Nat. Mus., No. 8515), and by Dr. John C. Merriam (Pal. Col. Univ. Cal., No. 854). Also obtained from a gulch half a mile northwest of the Belshaw ranch, the next ranch east of Van Horn's, by F. H. Knowlton, July, 1901 (U. S. Nat. Mus., Nos. 8994, 8995).

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a Cret. and Tert. Fl., p. 172, Pl. XXVIII, fig. 15, 1883.

b Idem, p. 173.

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