234 MISS MARIETTA PALLIS ON THE 
В. flavescens, Gren. & Godr.* In structure it is closely related to the 
fens of Bast Anglia, which in their early stages are usually formed of reed, 
Phragmites communis, Trin. (see Pl. 24). In Rumania, Plav is practieally 
confined to the delta of the Danube, where its distribution is wide though 
sporadic. 
It has two well-marked portions, an aquatic and an aerial. The aquatic 
portion consists of interlaced reed-rhizomes, closely bound together by the 
numerous branched water-roots of the reed (see p. 250, and Pls. 11-16), 
which retain much soil, and thus completely fill the interstices between the 
rhizomes. Hence there results a compact raft-like structure, the general 
surface of which projects about 4 em. (about 14 inches) above the surface 
of the water, and measures from about 0°8 m. to about 2 m. (about 2 feet 
8 inches to about 6 feet 63 inches) in thickness. From this raft rises a 
thicket of reed (see Pls. 18-20), formed of the aerial continuations of the 
reed-rhizomes, that is, both of sterile leaf-bearing and flower-bearing branches. 
The flower-bearing extremities often measure as much as 5°15 ш. (about 
17 feet), and the total length of the shoot, viz. vertical rhizome plus 
aerial extremity, sometimes reaches a length of 7:15 m. (about 23 feet 
6 inches). 
The areas covered by Plav are not in general great, and owing to the 
dense and tall growth of the reed cannot easily be estimated. I have walked 
over many but have, with a single exception f, been unable to keep one 
direction for more than about 10 minutes, and I have usually encountered 
a break in the continuity of the Plav very much sooner. Measurements of 
Plavs are much to be desired (see p. 268). 
Plav was first described by Dr. Gr. Antipa, the Director of the Natural 
History Museum of Bucharest and Inspector-General for the Ministry of 
Agriculture and the Domains f, in a work published at Bucharest in 1910$. 
Dr. Antipa's description of Plav is short—and necessarily so—since the 
ж The nomenclature of the Rumanian plants is after D. Grecescu, “ Conspectul Florei 
Romániei," Bucharest, 1898. I have preserved the exsiccata used for the determinations. 
+ The exception is a Plav which according to the fishermen extends for several kilometres 
along the edge of Lake Lumina (see map and PI. 20. fig. 1). This Plav was reported to meas 
the largest, and it was certainly much the largest that lexamined. After half an hour's walk 
I had found no change in its structure, and therefore turned back as the time at my disposal 
was short. Long as this Play is, however, it is but a mere strip, roughly about 36 metres 
(about 39 yards) in width, on the gárla (girla: water-channel) side; it lies close behind 
the reed-swamp which at present abuts on Lake Lumina. I have not seen any Plav with 
both length and breadth great. Walking over Plav is naturally laborious, though expe- 
rience teaches how it can be done without inordinate loss of time. 
{ It was as Director of the State Fisheries, a branch of the Agricultural Service, that 
Dr. Antipa' became acquainted with Plav. 
$ Antipa, Gr., *' Das Überschwemmungsgebiet der Unteren Donau," Bucharest, 1912 ; 
a reprint in German from the “ Anuarul Institutului Geologic al Romaniei,” vol. iv. 1910. 
