46 J. O. HAGSTEOM, CRITICAL BESEARCHBS ON THE POTAMOGBTONS. 



f. (levestltus n. f. — Folia brevia. Ramuli 2:se et 3:Ee ordinis vix evoluti. 



On account of the short leaves and the absence of short branches this form 

 presents a very bare appearance. 



Distribution: Siveden, Scania Kullen (hb. Lund.). — Gothland, Bogevik, 82, 

 Andersson (hb. Lund.) 



f. bracJiypus n. f. — Differt a typo peduncuUs brevissimis, 10 — 30 mm. 



Distribution. 8. America: »Andes Ecuadorenses 1857 — 59, E,. Spruce, N. 

 5886 (hb. Lund.), a narrow-leaved »P. striatus», see p. 52. — Besides in hb. Stock- 

 holm, and Uppsal., labelled: sL. Kralik, PI. Cunetanse n. 136 et 395». 



f. coronatus Hagstr., Potamog. from As., in Bot. Not. 1905, 141: — Spica ssepius 

 multiverticillata (vertic. 5 — 8), fructus minor, 3 mm X 2 mm. 



Distribution: High-Asia: »Muntjokk-ott 23 Juni Mapiek-kolb (hb. Stockholm. 

 Univ.) 



f. subfEqual)ilis n. f. — Folia latiora, ramea et caulinia subsequalia. 



A rather broad-leaved form, with slight difference in width between branch- 

 leaves and stem-leaves. Recorded from England, River Leen, Mitchell (hb. Upp- 

 sal.) and from India, Panjab, Thobison (hb. Stockholm, and Uppsal.) 



f. trichopliyllus n. f. — Caidis tenuissimus, foliis trichoideis. 



Distribution: Spain, Iviza,, Camberfeder (hb. Stockholm.). — /toZt/, Palermo, 

 ToDARO (hb. Stockholm.). Besides in hb. Stockholm, labelled: »L. Kralik, PI. Cune- 

 tanse. N. 136, 1852 and 395». 



f. latiuseuhis n. f. — Folia prsesertim inferiora latiora ca. 2 mm lata. 



Distribution: Sweden, Stockholm, 59, Zetterstbdt (hb. Uppsal.). — Den- 

 mark, Omo, 64, Nielsen (hb. Uppsal.). — England, Benwick, Cambs. 85, Eryer 

 (hb. Stockholm.). 



Var. (liflfllSllS n. var. 



Ramosior et plerumpue colore Isetiore prseter formas flumineas. Folia omnia 

 ramulorum sensim attenuata acuta; caulina inferiora, 0,5 — ca. 2 mm lata, obtusa 

 cum mucrone minimo verrucseformi, media apice attenuata subacuta, summa angusti- 

 ora apice ± conspicue mucronata. — Fig. 18, A, B, C, D, L. 



This variety has usually a lighter brown colour except the river-forms, that 

 are of a darker green. It is easily recognizable on the leaf-apex gradually tapering 

 to a keen point. The involucral and basal stem-leaves, however, always have their 

 fixed form. 



V. diffusus is by far the most usual and widest spread form. In the Baltic 

 it can be considered as common, farther northwards it is more sparingly met with 

 in the south part of the Bothnian Gulf to sKvarken». In the northern section of 

 the Gulf it is only recorded from Ratan, Sweden, under the 64:th N. L., and from 

 Jakobstad, Finland (C. W. Fontbll, Beitrage etc. 1909, 4) a little more southwards. 

 To the north of the 64: th parallel it is not known to me, but S. Almquist (Hartm. 



