Særtiyk af Botanisk Tidsskrift -24. Bind 3. Hefte. Kolieiihavn 190-2. 



Arbejder fra den Botaniske Have i Kobenhavn. Nr. 6. 



Hydrocharitaceæ, Lemnaceæ, Pontederia- 



ceæ, Potamogetonaceæ, Gentianaceæ (Lim- 



nanthemum), N y m p h æaceæ 



by C. H. Ostenfeld — Copenhagen, 



Hydrocharitaceæ. 

 Blyxa ïhouars, 



1. B. sp. {octandru (Roxb.) Planch.?). 



It is impossible lo determine the collected specimens of Bhjxa because 

 they are sterile. 



Rice-field near Lem Dan. 



Area (of B. o<:tandra): Tropical Asia and Australia 



Halophila Thouars. 



2. II. oralis iR. Br.i Hook, fil., Fl. Tasman. II, p. 45; B.Balfour, On 

 the Genus Halophila, Transact, and Proc. of the R. Soc. Edinburgh vol. XIII, 

 1879, p. :290; CauUnia ovcdis R. Br., Prodr. Fl. Nov. Hollandiæ p. 339; 

 H. ovata Gaud., in Freycinet, Voy. Bot. p. 4:29, t. 40, f. 1 ; Hook, f., Fl. 

 of British India V, p. G63. 



The few present specimens which are sterile, belong to f. minor 

 (Zoll.) Aschs., Linnæa 1867, p. 174 (Leninopsis minor Zollinger, Verzeichn. 

 1854, p. 75). 



Between Koh Riat and Koh Mesan, in 3—5 fathoms water (coral-sand). 

 Area: Shores of the Indian, Malayan. Australian and Pacific Oceans (from 

 the Canal of Suez to Luchnan Islands (Japan)). 



3. H. decipieiis Ostf., n. sp. 



Leaves oblong-elliptic, their ventral .surfaces hairless, but their 

 dorsal surfaces and the margins covered with very fine, short, uni- 

 cellular star hairs or teeth: the same hairs are found on the out- 

 side of the scale- and spathe-leaves ; from the midvein of the foliage 

 leaves 6 — 9 lateral veins pass on each side outwards to the intra- 

 marginal vein; the petioles ^^2 — ^1 time as long as the laminæ. 



Plants monœcious, flowers unisexual, 1 male and 1 female 

 flower enclosed in the spathe-leaves, corresponding in regard to 

 structure etc. very closely with those of H. Baillonis (see: Theo. 



