58 



J. O. HAGSTROM, CR1TICAL RESEARCHE3 ON THE POTAMOGETONS. 



P. crispus L. 



Species plantarum 1753, 126. — P. serratus L. 1. c. — P. erenulatus Don, 

 Prodromus Fl. Nepal. 1902—3, 22. — P. luberosus Roxburgh, Hortus beng. 1814, 

 12. — P. serrulatus Schrader ap. Opiz, Flora V, 1822, 227. — P. crispatus Wall- 



man ap. Fries, Nov. fl. Suec. 1828, 

 43. — P. laclucaceus Montand., 

 Guide Bot, 1S68, 305. Hue 



etiam species Gandogeriame perti- 

 nent: P. hungaricus, P. rubricans, 

 P. pattidior, P. Hohenaclxri, P. 

 Notarisii, P. leptophyllus, P. n<- 

 brincevus, P. macrorrhyncus et 

 P. austriacus Gandög., Pugillus 

 plant. nov. etc. in Österr. Bot. 

 Zeitschr. 1881, 43-44. Fig. 



21, 22, 24, A. 



The furrowed stem and serru- 

 late leaves connect this plant with 

 the precedent group. An abund- 

 ant evolution of hibemating and 

 propagating cauline buds char- 

 acterizes this species as well as 

 the foregoing and next-following 

 groups. The air-channels of the 

 leaf, in the upper part 1—2 on 

 each side of the raidrib, increase 

 in number toward the base, form- 

 ing there a broad area of 4—5 

 rows on each side. One or two 

 pairs of lateral ncrves are runniug 

 rather near the margin, by which 

 (hr species exhibits affinity with 

 the Pusilloids espeeially P. obtusi- 

 folius. The ligule is of ten at its 

 li;is(> slightly grown together with 

 the leaf, a fact observed in /'. ochrealus also. 



The style is elongated and the oval stigma fixed obliquely. By this fart the 

 present species and group is distinguished from its relatives; also by the ovsries, 

 which at first isolated from each othcr grow a Little together below, vrhen ripening 

 to fiuit and incrcasing simultaneously fcheir reoeptaole. The rostrum, in fresk statc 

 being conio and erect, eurves itseH more or less backwards, wlicn drying, by bhe 

 dorsal spongy parts of it shrinkin<_ r mor<> t han (lic inside. The dorsal k»'*'! ends in 



Fig. 2\. I', crispus L. A, It, C, Tops "i' Btem-leaves of the var. ob- 

 tusifoliiu Fibb. (slightly enlarged); /', Upper part of a stem-leaf of v. aeuti- 

 foldts Fhb. (slightly enlarged); A', PistÖ, lateral view, «. the point vhere 

 it is flxed at the receptaele, st, stigma, f; /■', Longitndinal section of the 

 receptaele (a) with two fraits showing the poinl of oonoretion (j>), o, rostrnm, 

 <•, dorsal keel with a basa! horn-like bo^s. | ; <;. Fignre showing the rela- 

 tive Bize of the pollen-grains of, <i. P. crispus, i>. I', perfoliatus and pralongus, 

 r, p, pusillus; II, Diagram of the stera'8 axial cylinder, /.-, bnndles, ir, bnndle 

 trio, dr, opposite bnndle, //>, lateral bnndles, p, pith; K, Transverse section 

 of the middle lacnnar pari of a Leaf (npper part noar the middle), "<, mid- 



rib, *,"-. /., Part oi the leal margin with '_' teeth eael ling in s greater 



top-oell, <( (enlarged); M, Transverse section of leaf margin, ».■.■. apper 

 snrface, t», lower snrface, />, a faiut marginal strand. ',". 



