124 PISTIACEJE. 
longit. lateral. et extrorsim dehiscent. Pollen ovatum, hinc 
sulcat. Stylus brevus apice 3 fidus. Stigmata 3. papilloso- 
capitata, lutea. Ovarium obsoleti 3 gonum, | loculare, placentis 
latis, 3 parietalib. Ovula plurima, foramen hilo opposit. 
Hab. Yn arenosis siccis, sub humidisque. Mergue: October 
1834. 
Folia marginib. denticulato-scabris, scapis subancipitibus 
subteretibusve: (4-6 uucialib.) foliis linearib. acutis, subeve- 
niis marginibus denticulato-scabris, capitulis subglobosis, 
squamis apicibus carinat. nervo medio nempe prominulo dis- 
coloreque X. scabre affinis excharactere Br. Pr. 
PISTIACE E. 
> Pistia. 
Pistia stratiotes. Pl. CLXI.B. 
This plant consists of a depressed shortened axis, of 
a somewhat bulbiform shape. Inferiorly this gives origin 
to the roots, which at first, and until they have reach- 
ed some length, are simple; they then become verrucose, 
each protuberance marking the exit of a radical fibre. The 
adult roots are very much branched, especially towards their 
bases, the apex of each radical fibre is enclosed in a membra- 
nous brownish sheath. The /eaves do not appear to have any 
definite order, they are almost sessile cuneiform obovate, sub- 
repand slightly emarginate, entire, 5 veined. The veins are not 
very minutely subdivided : they are prominent on both sur- 
faces, particularly the under one. The middle vein alone 
reaches the point of the leaf, its termination is indicated 
` by а brown spot, to this point the lateral veins converge. 
Both sides of the leaf are equally clothed with white, nearly 
erect, very abundant jointed pubescence. The axillz of the 
leaves give origin to the inflorescence : the lower angle of their 
origin from the stem in the lower leaves, sends out roots. The 
L 
inflorescence is axillary, spathaceous, pedunculated. The 
