Observations on the Flora of Japan. 



{Continued from p. 128.). 



By 

 T. Makino. 



Isoetes (Aquatics) echinospora Durieu in Bull. Soc. Bot. France, 

 VIII. p. 164; A. Braun in Verhandl. Bot, Ver. Brandenb. (1862) p. 24; 

 Babington in Journ. Bot. (1863) tab. 1 ; Milde, Fil. Eur. et Atl. (1867) p. 

 279; Baker in Journ. Bot. (1880) p. 67 ; Id. Handb. Fern- Allies (1887) p. 

 125; Enge]m. in Trans. S. Louis Acad. Sc. IV. (1882) p. ; A. Gray, 



Man. Bot. ed. 5, p. 676 ; Sadebeck in Engler et Prantl, Nat. Pflanzen- 

 fam. I. 4, p. 776. 



Calamaria echinospora 0. Kuntze, Rev. Gen. PI. II. p. 828. 



Isoetes lacustris subsp. echinospora Hook. fil. Stud. Fl. Brit. Isl. ed. 

 2, p. 505, et ed. 3, p. 526. 



var. asiatica Makino var. nov. 



Spqrangia unspotted, |-| covered by a broad velum. Leaves icith- 

 out stoma. Spinules of the. macrospore stouter. Microspore smooth. 



Small, wholly submersed. Caudex 2-lobed, about 7-20mm. across, 

 blackish brown ; lobes hemispherical or compresso-hemisphserical, the inner 

 side densely emitting pale brown ( but darkish brown when dry) roots. 

 Leaves tufted, erect or erect-patent, about 8-30 in number, 3|-I4 cm. long, 

 l^-2i mm. across in the middle, darkish green, pale and pellucid and some- 

 times rosy towards the base, stifBsh, straight or sometimes somewhat re- 

 curved, subulate, gradually tapering to the point which is obluse under lens, 

 septate, subterete and slightly plane in front, but broadly concave in front 

 and lunate in section below, the lower edges thin and decurrent from the 

 dilated and concave phyllopode, which is deltoid or broadly deltoid in form 

 (4-7 mm. long, 5-11 mm. broad) and membranaceous on the border and 

 closely imbricated. Velum orbicular to elliptical, with a semiorbicular to 

 elliptical opening below extending to the middle. Ligule cordato-semiorbi- 

 cular or lato-cordate, membranaceous towards the margin, 1^-lf mm. across. 

 Sporangia orbicular to elliptical, truncated or retuse at the upper end, com- 

 pressed, thinly membranaceous, pale, 2|-4 mm. long. Macrospores white, 

 globose, but very slightly depressed, marked on one hemisphere with a tri- 



