119 



Makino ! Sept. 1893, herb. Be. Coll. Imp. Univ. Tokyo) ; Prov. Iwaki : 

 Mimikai in Narnekata-gori (T. Makino ! Aug. 16, 1890), Yotsukura (T. 

 Makino ! Aug. 14, 1890); Prov. Iwashiro : Moniwa-mura (T. Makino \ 

 Sept. 2, 1890) ; Prov. PvIkuzen : Iwanuma (T. Makino ! Aug. 17, 1890), 

 Iwakiri (T. Makino ! Aug. 1890). 



This species is frequently found in rice-fields and marshy places through- 

 out Japan, and it is the only representative of Japanese Elatinece. It 

 comes nearest to the Elatine triandra Schk., but it differs from it especially 

 by its 3-parted calyx and the aspect of the rugosity of the testa of seeds. 

 Franchet et Savatier's Elatine triandra (Savatier, n. 141) from Yokosuka 

 in the Authors' Enumeratio I. p. 54, which Maximowicz referred to his 

 Elatine teirandra in Melanges biologiques XII. p. 723, certainly belongs to 

 my species, and the plant which I collected in the province of Tosa of 1*1. 

 Shikoku, and sent to Maximowicz, and cited by him in the same paper, is 

 not likewise truly the Elatine tetrandra, but E. oriental is Makino. 



Tillgea aquatica Linn. Fl. Susc. n. 156, et Sp. PI. p. 128. 



Glabrous pygmy annual, 2J-5J cm high. Roots fibrous, delicate, 

 white, densely sendiug from basal nodes of stems. Stem erect or ascend- 

 ing, simple, or alternately or oppositely branched usually in the lower por- 

 tion, or sometimes ciespitose usually with the outer branches which are 

 decumbent and radicant at the base, terete, subsucculeut, smooth, virescent 

 often tinged with reddish colour. Leaves opposite, sessile and connate at 

 the base, patent or erect-patent, linear-lanceolate, acutish, entire, rather 

 fleshy, smooth, virescent. with an immersed midrib, the largest one about 

 7 mm long, 1mm broad. Flower 4-merous, minute, about 1| mm long, 

 I mm across, solitary at the leaf-axil, alternately disposed, very shortly pedicel- 

 late, ebracteate, with a fleshy receptacle. Sepals erect-patent, connate at 

 the base with obtuse sinuses between them, ovate-oblong, broader below, 

 entire, obtuse often with a few minute teeth at the apex, a little shorter than 

 one-half of the petal, smooth, herbaceous, virescent, one-nerved, persistent. 

 Petals not patent, nearly erect, free, alternate to the sepals, ovate-lanceolate 

 or ovate-oblong, entire, obtuse with obscure and minute teeth at the apex, 

 white, smooth, thinly membranaceous, nerveless, concave internally and em- 

 bracing the ovary, imbricate in bud, persistently remaining and closely adher- 

 ing to the back of the follicles. Stamens free, alternate to the petals and 

 shorter than them ; filament subulate-linear, white ; anther minute, didy- 

 mous. Hypogynous scales 4, opposite to the ovaries and closely placed on 

 the lower back of them, free, minute, clavate-linear, obtuse at the apex, 



