158 



J. O. HAGSTROM, CRITICAL RESBAEOHES ON THE POTAMOGETONS. 



but the differences from P. Gheesemanii cannot be explained from that fact, at least 

 not the short upper petioles, broader lamina, and the above described little cusp. The 

 pistil is also another and likeweise the stem-anatomy. I refer to what is said under 



P. Gheesemanii and to the figures 75 and 91. 

 Although I have seen no ripe fruit and, besides, 

 but inconsiderable materials, I do not hesitate to 

 consider it as a distinct species which may ad interim 

 be united with the a^nplifolius-growp. 



Distribution. New Zealand, Waihi stream, 

 (I / Waikato, N. Isl., 84, Cheeseman (lib. Stockholm). 



P. Fryeri Ar. Bennett. 



Two new Japanese Potamogetons, in The 

 Journ. of Bot., 1907, 234. — Fig. 76. 



The plant from Japan, Kiusiu, preserved in 

 hb. Stockholm, no doubt belongs to this species, 

 although the long spikes do not answer to the 

 description. The spikes are in flowering state 30— 

 40 mm, and deflorate 40 — 50 mm long. P. Fryeri 

 is said to have the spikes merely 2 cm in length 

 and the peduncles thickened above, which is not 

 the case with here accessible materials. A very 

 significant property of the Kiu-Siu plant is 

 [ the long-petioled perianth-leaves. Limb broadly 

 ,^ep rounded and shorter than the claw. Pollen of 

 middle size and spheric. Styles elongated and in- 

 crassate upwards, with oval, rather small stigmas. 

 There would be no hesitation if the anatomic 

 diagram of the stem were given in the description. 

 The plant here referred to has the following stem- 

 structure: The epidermis, which consists of large- 

 roomed cells, has a one- or two-celled strengthening 

 layer with bast-bundles scattered at intervals. 

 These pseudo-hypodermal bast-bundles often show 

 an inclination of moving a little inward to the 



Fig. 76. P. Fryeri Ak. Bennett. A, The 

 iietliermost leaf of the stem, \. B, The lowest 

 leaf but one, blade, -}. C, Involucral leaf, base 

 and top of the blade (blade ± 80 X ± 35 mm). 

 />, Perianth leaf straightened, and magnified, with 

 anthers. E, Pistil, a, side-view, b, from the inside, 

 c, stigma from above, ^^. F, Part of a ligale in 

 cross-section at base showing a ridge and some 

 bundles, -[-. G, Part of a cross-section of the 

 stem, Y, tr, bundle-trio, Iqi, strengthening layer 

 with 3 bast-bundles, ep, epidermis, sh\ cortical 

 bundles, cc, central cylinder. 



radial interlacunar walls. Interlacunarly there are 

 2 to 3 circles of bast- and vascular bundles (see the fig.). The endodermis consists 

 of 0-cells and the central cylinder has ten free vascular bundles, six of which are 

 lateral and 4 median, the arrangement consequently being prototypic as in P. 

 pulcher. 



