The phylogenetic relationships of the genera of Lecythidaceae and represent
atives of Scytopetalaceae were assessed using cladistic analysis of both mo
lecular (rbcL and trnL sequences) and morphological data. The results show
that the pantropical family Lecythidaceae is paraphyletic. Support was foun
d for the monophyly of three of the four subfamilies: Lecythidoideae, Planc
honiaideae, and Foetidioideae. The fourth subfamily, Napoleonaeoideae, was
found to be paraphyletic, with members of the Scytoperalaceae being nested
within it forming a strong clade with Asteranthos. Both families share a nu
mber of morphological features, including several distinct characters such
as cortical bundles in the stem. The combined analysis produced three trees
of 471 steps and consistency index CI = 0.71 and retention index RI = 0.70
. Asteranthos and members of Scytoperalaceae should be treated as a subfami
ly of Lecythidaceae, while Napoleonaea and Crateranthus (the latter based s
olely on morphological features) should remain in the subfamily Napoleonaeo
ideae. The Lecythidaceae are recircumscribed, and Asteranthos and members o
f Scytopetalaceae are included in Scytopetaloideae. A formal taxonomic syno
psis accommodating this new circumscription is presented.