. Critical researches on the potamogetons. KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 55. N:0 5. 41 P. jlahellatus Bab. may nowadays by all investigators be acknowledged as a fectinatus-iovva. Common characteristics of the numberless forms of this species (das Chamaleon unter den Laichkrautarten: E. Baumann) are the elongate, sharp points of the youngest leaves of the sterile short-branches, the cuspidate involucral leaves with a more or less conspicuous mucro, the more or less broad, hght (whitish—pale- green—whitebrown) membranous border of the sheaths, the large, oblong-shaped or ovoid (ra
. Critical researches on the potamogetons. KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 55. N:0 5. 41 P. jlahellatus Bab. may nowadays by all investigators be acknowledged as a fectinatus-iovva. Common characteristics of the numberless forms of this species (das Chamaleon unter den Laichkrautarten: E. Baumann) are the elongate, sharp points of the youngest leaves of the sterile short-branches, the cuspidate involucral leaves with a more or less conspicuous mucro, the more or less broad, hght (whitish—pale- green—whitebrown) membranous border of the sheaths, the large, oblong-shaped or ovoid (rarely almost spheric) pollengrains, the more or less conspicuous styles with sloping stigmas, and the more or less large (3—4,5 mm X 2—3 mm) fruits, whereto is to be added the way of branching (fig. 15, B) and producing its spikes, B. Fig, 15. P. pectinalui L. A, Hibernating rhizomatic tnrio {nat. size), deprived of its basal scales; f^ prophyllum, s?, scale-leaves, /, //, ///, the dift'erent generations of the tnrio, 1, 2, 3, 4, 5, 6, their different internodes. The dotted lines indi- cate the places for concretion of internodes. The 3d and 4th internode of the different generations partake in forming the bnlbs, cf. fig. 3, C, Df B, Ramification, somewhat schematized, -]; a, mainshoot, h, leaf with sheath and lignle (rf), clasping the basal parts of 3 evoluted branches {1, S, 3), f, prophyllum, I', I", scale-leaves, <-, first laminated leaf of the branch 1. The first three internodes of this branch are commonly very short, together only about one mm. Or only the first two internodes are short (about 1 mm) and the third one elongated, the sheath therefore clasping only two branches, or, if I' is sterile, one single branch. From the scale I" occasionally springs a rhizome; f is always sterile, cf. Fig. 11, D. C, Transverse section of young sheath, basal portion, showing the site of the free borders, rt, h, as in Fig. 3, B, '^^. D, Pistil, lateral view showing
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Keywords: ., bookcentury1900, bookcollectionbiod, bookdecade1910, bookyear1916
