98 
polygonifolius, chiefly depending on the shape of the style, 
stigma and fruit, that till now not have been examined, and 
on the margin of the submerged leaves, that probably is 
even, but of course can be serrulate, which only on very 
young shoots can be stated. However it 
is, without consideration to the anatomy, 
easily recognizable on the small oval 
long-petioled upper leaves and soon de- 
caying stipules and submersed leaves, 
The plant belongs to the flora of 
Madagascar. The specimens examined 
are labelled >flora von Central-Madagas- 
car. N:o 4031. Statio: Imerino: pr. Ta- 
nanarive. Leg. J. M. Hildebrandt 1880. 
Comm. C. Reusch.» and belong to the 
museum in Bremen. 
Potamogeton stylatus n. sp. 
Caulis humilis simplex teres, in 
axillis foliorum floralium ramis primæ 
— 2:e ordinis prolongatus internodiis 
3 — 5 cm longis; folia rami secundæ ordi- 
nis subcoriacea breviter petiolata lingu- 
lata; cetera membranacea, margine levia, 
sessilia ovalia, basi ovato, obtusa curvata 
1. Pot. paruiatus undulata, ^ ^ mm; stipulæ 10—20 mm 
Hagstr. Floatingleaf. 
Nat. size. longæ tenues deciduæ; Pedunculi æquales 
Hagstr. Top of a 3—4 cm longi; sptca florens lo— 20 mm. 
stem-leaf. Nat. size. Stylus conspicuus, stigma oblongum. 
Probably it is this species, that has been taken for 
P. alpinus in Boissier, Flora orientalis. V. 1884. 16., but it 
differs by the short oval leaves and especially by the stem- 
structure with its cortical bastbundles occurring along the 
epidermis und sometimes even with some or other bundles 
farther inwards in the cortex. The stele exhibits in a trans- 
verse section an oval form with two median channels and 
