KUNQL. SV. VET. AKADEMIENS HANDLINGAR. BAND 55. N:0 5. 



15 



To this may also be added biological and anatomical differences. 



The matter with the turios stands thus: As to their nature they are rhizoma- 

 tic. A turio (Fig. 3, C, D) consists of two (or rarely three) generations of shoots in 

 budstate. The third and fourth internodes of the first generation swell to an oblong 

 form and likewise the first to the fourth internodes of the second generation while a 

 concretion, indicated by a dotted line (in D), partly takes place between the third 

 internode of the first generation and the first internode of the second generation, 

 the whole only about 15 mm in 

 length. P. vaginatus behaves in 

 quite like manner (fig. 11, E), 

 whereas P. pectinatus has its own 

 way (fig. 15,^). 



The spike-bearing branches 

 behave as is shown in the fig. 

 2, A and the stem seldom pro- 

 longs itself by spike-bearing bran- 

 ches from the involucral leaf-axils. 



On the way of ramification 

 see Hagstrom in Neuman and 

 Ahlfvengren, Sveriges Fl. 1901, 

 793. Each leaf-sheath clasps a 

 single branch. 



Anatomy. The epidermis of 

 the stem consists of very long and 

 narrow cells in contradistinction to 

 P. vaginatus (the main-form) with 

 very short almost cubic epidermis- 

 cells. The statement of C. W. 

 FoNTELL (Beitrage anat. Baties 

 Pot. 1909, 27): — »Die Epider- 

 miszellen in verschiedenen Teilen 

 des Stammes wie bei P. vaginatus» 



etc. is misleading, evidently depending on an incomplete investigation, the author having 

 only observed the cells in transverse section. They are inside covered with an one- 

 layered pseudo-hypoderma, at the base of the stem rarely two-layered. Inside the 

 epidermis occur a few (2 — 4) circles of lacunae or air-channels, the wider outward, 

 the narrower inward as usual. The inmost bark-part consists of one or a few layers 

 of cells placed close to each other and along the endodermis as usual. The endoder- 

 mis consists of faint u-cells. Between the corner-cells of the air-channels the corti- 

 cal (vaginal) strands are drawn forth, at the basis of the stem forming a circle of 6 — 8 

 (10) strands, higher up of only 4 — 2 — strands. In the peduncle and rachis they have 

 entirely disappeared. The central cylinder has a rounded crosscut-form of the four- 

 bundled type, basally in the stem passing into an eight-bundled arrangement. The 



Fig. 3. P. fHiformis Pehs. A, Pistil, lateral view, ^y"; stigma horizon- 

 tally extended over the whole surface of the style. B, Transverse section 

 of a very yonng leafsheath at hase showing three vascular bundles, the 

 midrib, «, and the lateral nerves h-h (corresponding to a and b-h in the 

 next figure) and four mechanical strands; Z, airchannels, p^ plicate part fi- 

 nally bursting, -■^. C, Turio {-. Z>, The same, -J, deprived of its scales and 

 their places signed with f, prophyllum and si, scale-leaves; I, II, first and 

 second generation; 1, 'J, 3, 4, different internodes of these generations. 

 E-B, Different forms of the leaf-apex showing the midnerve, the thin mar- 

 ginal nerves and the cross-walls of the lacunre, y. A', common form. F, 

 common form tipped with a very faint wart. (?, var. Macounii Mor. iT, varr. 

 rlvtcolns Hagsth. and iibeianus Haostr. 



