KUNGL. SV. VET. AKADEMIENS HANDLTNGAE. BAND 55. N:0 5. 



179 



belg. 1827, 163. — P. Hornemanni Meyer, ex Koch, Synopsis, 1837, 674. — P. 

 microcarpus Boiss. & Reut., Diagn. PL nov. Hisp, 1842, 24? — P. siculus Tineo 

 ap. GussoNE, Fl. Sic. Syn., II, 1845, 790. — P. subflavus Lobet & Barrandon, 

 Flore de Montpellier, 1876, 671. 



The floating leaves of this species are generally thinner than in other species 

 dependent on a reduction of the palisade-tissue into one or 2 cell-strata of cubic cells 

 without the air-rooms appearing there otherwise. Rarely we meet with leaves with 

 air-cells in that tissue, which then is very like ordinary palisade tissue. Apex of 

 the floating leaves usually obtuse without distinct cuspidation or 

 pointing (see fig. 93, B). Exceptionally there are individuals with 

 the upper leaves cuspidate. I name this form: 



f. cuspi(latu.s n. f. — Folia superiora cuspidata (vide fig. 93, A). 



Sometimes the floating leaves are small, 20—30 X 10 — 15 

 mm, and the submersed leaves narrow: 



f. subflavus n. f. — P. suhjlavus Lor. & Barr., 1. c. — Spe- 

 cimens from France, Mauguio (Herault) 73, Loret and others 

 (hb. Stockholm, et Lund.) and from Germany, Daunstadt (Palati- 

 nat) 55, Schultz (hb. Stockholm, et Uppsal.). 



This plant is still held for a subspecies of P. alpinus Bale. 

 by Prof. P. Graebner in his Synopsis der Mitt. Fl. 1912 p. 476 

 (2d ed. Ill Lief.). Prof. G. Fischer writes (in Fedde, Repert. 

 1914) of the same plant: — »certe et habitu et fructu distat a P. 

 alfinus Bale, et accedit ad P. coloratum. Utrum autem subspe- 

 cies vel proles P. colorati, an planta hybrida inter P. coloratum 

 et P. alpinum (vix P. polygonifolium) habendus sit, adhuc am- 

 bigiturs. 



The Heraultian plant is without any doubt a true form of 

 P. coloratus and not at all of a hybrid origin. — 



A form with rounded, ovate, superior leaves, ca. 30 X 24 mm, 

 is V. rotundifolius Mert. & Koch. — Now and then forms appear 

 with very large leaves, 70—80 mm long or more, by 30 — 45 mm 

 broad : 



f. grandifolius n. f. — Folia amplissima, 70 — 80 X 30 — 45 mm. 



Var. pacJiystachyus Rchb. has thicker spikes than the other forms (not seen by 

 me). — Var. jamaicensis Grisbb., to judge from the description, may not at all be- 

 long to this species, the plant occurring aside from the distribution-area, and the 

 fruit being half as large as in P. lucens and sharply keeled, the stipules keeled etc., 

 see Grisebach, Fl. Br. West Ind. Isl. 1864, 506! 



The terrestrial form, f. tcrrestris TiSELius, is very often seen. 



Distribution. Siveden, Scania, Eskilstorp, 91, Larsson and others (hb. Stock- 

 holm., Uppsal, Lund.), Bulltofta, 94, Johansson and others (hb. Stockholm., Upp- 

 sal., Lund.), Arrie, 67, Tullberg and others (hb. Stockholm., Uppsal., Lund, et 

 Gothob.). Blelcincj, Marielund, Aspegren, hb. Hartman (hb. Uppsal.), labelled: 



Fig. 93. P. coloratus 

 Vahl. vl, Involucral leaf 

 of the form citspUlatits Hag- 

 STU. \. B, Top of an in- 

 volucral leaf of the com- 

 mon form, -J. 



