JUBA.SSIC PLANTS FROM KAGA, HIDA, AND ECHIZEN. 39 



21. Equisetum ushimarense m. 

 PL XL fig. 1—3. 



Rhizome ribbed ; iwfegrs roundly ovate, single or joined like beads.. 



The three specimens here figured I believe to belong to one and 

 the same species. They all represent underground stems which are 

 generally slender. In fig. 3, these stems measure H — 2 mm. in 

 breadth with internodes 15 — 20 mm. in length, and are seen with 2 — 3 

 strong ribs. Tubers are of various shapes owing to distortions under 

 pressure ; but in general they are roundish or roundly-ovate and single 

 or rarely joined like beads. (Fig. 3, small ones on the left). In fig. 

 3, the diameter of these tubers is approximately 5 — 9 mm, while in 

 fig. 2 (right) a slender rhizome only 1 mm. broad possesses a large 

 tuber 15 mm. long and 13 mm. broad, in fact the largest we have. Fig. 

 1 shows comparatively a broad rhizome (5 mm.) with 3 — 4 strong ribs 

 and a tuber 8 — 11 mm. in diameter. Sometimes these underground 

 stems are still seen with root-hairs attached. 



It is much to be regretted that no overground stem was found 

 with these remains. 



Equisetum Buchardti Sell imp. (Schenk, Flora der nordivestdcutseh . 

 Wealdenform., p. 205, pi. XXII, fig. 1 — 5) from the Wealden exhibits 

 quite a similar kind of spherical tubers which are said to have been 

 tridentate at the apex. An Oolitic species with tubers has been des- 

 cribed by Heer (Beigtr. z. Jurafiora Ostsib. u. d. Amurl., 1876, p. 99, pi. 

 XXI I, Jig. 5 — 7) from Bureja, which however had them more elongated 

 than in our own. 



Numerous in a greenish-grey arenaceous shale at Ushimaru. 



22. Equisetum sp. 

 PL XII, fig. 7. 



Only a small fragment of an overground stem was obtained, 



