KTTNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 55. N!0 5. 



159 



Distribution. Japan, Kiusiu, Kundalo-San, 1863, Maximowicz (hb. Stockh.). 

 I have also seen specimens from »Hakodate Arigona», gathered 12 /24 june 1861 by 

 Maximowicz, it. sec. (hb. Petersburg), and from Ins. Saghalien, 08, Faurie (hb. Haun.). 



end 



oao 



vb 



( sm 



e P 



P. plciophyllus n. sp. — Fig. 77. 



P. natans L. f. indica Miq., Fl. Ind. Bat. Suppl. 1, 1860—62, 259, 597? Cf. 

 Miq., Flore de 1'Arch. Indien, 1870—71. 



Caulis 30 — 70 cm. altus teres tenuis simplex vel inferne ramulis brevibus, in- 

 ternodiis ca. (10 — ) 60—120 mm longis. Folia infima linearia fihformia, 100 x 1 mm, 

 ± acuta, 3-nervia; superiora ± coriacea numerosa petiolata, petiolis tenuibns 50 — 110 

 mm longis, lanceolata vel basi ± rotundata, apice 

 brevissime et ± obtuse cuspidata (»les feuilles na- . 

 geantes sont plus ou moins elliptiques au sommet 

 aigués, å la base aigués ou presque aigués»: Miq.), 

 35 — 70 X 10 — 18 mm, 11 — 13-nervia. Ligulce tenues, 

 20 — 40 mm, inconspicue bicarinatse, fuscescentes 

 deciduse, 5— 6-nervi8e. Spec. sine fructu. 



Tall specimens of this species are easily re- 

 cognizable by the numerous (10 — 12) and slenderly 

 long-petioled small leaves with more or less cori- 

 aceous blades even beneath the primary spike. 

 The lowest leaf, at least in deep-water specimens, 

 lacks limb, whereupon follows one or a couple of 

 transitional leaves with very slight limb (10 — 20 

 mm). In shallow-water specimens those transition 

 leaves seem to be the very nethermost. 



Stem-anatomy : Central cylinder with 2 median and 6 lateral free bundles, 

 O-endodermis, one circle of interlacunar bast- and vascular bundles in the cortex 

 and no or extremely few subepidermal strands, epidermis without, or endowed with 

 a one-celled strengthening layer. 



Miquel has looked upon this plant as a variety of P. natans. I am inclined 

 to think that his f. indica consists of both P. pleioph. and P. digynus. 



Distribution. Asia, India: Khasia, Hooker & Thomson (hb. Lund). — Speci- 

 mens from »Alatan pandjang, W. K. Sumatra» (leg. Teysmann) seem to me to 

 belong to this species, or possibly rather to P. digynus (perversus). — China, Yunnan, 

 and Formosa, 1. Henry (hb. Haun.). 



Fig. 77. P. pleiophyllus Hagstb. A, Top of 



the lowest submersed leaf, {. B, Blacle of a 

 floating leaf showing the usual shape of it, J . 

 C, Part of a transverse section of the stem, °- 1 v , 

 sfr, subepid. strand, cc, central cylinder, end, 

 endodermis, vb, cortical bnndles, ep, epidermis. 



P. Stagnorum Hagstr. ap. R. E. Fries, Bot. Unters. in Wiss. Ergebn. schwed. 

 Rhod.— Kongo-exp. 1911—12, I, 1915, 187, fig. 16. — Fig. 78. 



Caulis ca. 30 cm altus simplex teres vel subteres. internodiis inferioribus 50 — 75 



