IV. On the Barringtoniacem. By Јонх Mars, F.R.S., F.L.S., Dignit. et Commend. 
| Ord. Imp. Bras. Rose, &c. 
(Plates X.-X VIII.) 
Read June 3rd, 1875. 
THE Barringtoniacee form an extremely natural group, offering very distinct and 
uniform characters; they differ from the Myrtacee in their alternate leaves without 
pellucid dots, in another kind of inflorescence, and in a fruit of very different structure. 
The inflorescence is either terminal and thyrsoid, with several approximated flowers, 
often of extraordinary dimensions, fixed upon a thick erect terminal stem, or more 
generally consisting of smaller flowers, spicately arranged upon long terminal pendulous 
racemes, sometimes subaxillary, or more rarely in branching panicles; but in all cases 
the flowers are formed upon one uniform plan. 
The leading character of this floral structure is, that their very numerous long slender 
stamens, in many series, are united at their base into a shortish erect monadelphous tube, . 
seated on the outer margin of a horizontal annular epigynous disk, from which they all 
fall off together, thus differing essentially from the Myrtacee, where the similar stamens 
are always free, each seated independently upon a perigynous annular disk, from which 
they fall off separately, leaving upon it many cicatrices, marking the several points of 
their previous attachment upon it. There is little analogy in this respect with the struc- 
ture of the Lecythidacee, where the short small stamens are separately supported upon 
numerous distinct processes, attached to a large petaloid organ (androphorum), of which 
no parallel is to be found in any other natural order. 
Another peculiarity of the Barringtoniacee is, that the tube of the calyx, agglutinated 
to an inferior ovary, is expanded above into a free limb, which in many cases offers the . 
very singular feature of being vesicoid, quite entire and undivided in the bud, marked 
by many parallel nerves, all meeting in a mucronate point in the apex ; after a while, by 
uniform internal pressure, caused by the growth of the petals and stamens, this limb 
becomes ruptured along the nervures, splitting into 2, 3, or 4 subequal segments, which 
eventually, little changed, are persistent, and crown the summit of the fruit. In other 
genera of the family the limb of the calyx consists of 4 free, small, rounded sepals, slightly 
imbrieated in sestivation; in a single instance it is cup-shaped, with an almost entire 
margin. 
The petals, constantly 4 in number, are generally 3 or 4 times as long as the 
calycine limb, are oblong, rounded, narrowing towards their base into fleshy claws, 
which are agglutinated to E. monadelphous tube of the stamens so firmly that all fall 
off together. 
H 2 
