592 
Pratn.—A Review of the Genera 
Before Mueller’s criterion can be considered it is desirable to provide, 
what so far has never been fully given, an account of the fruit and the seed 
of Erythrococca aculeata , Benth. The fruit of this species 1 is occasionally 
3-coccous, all three carpels becoming fully developed ; more often it is 
2-coccous and didymous, not infrequently it is, by abortion, i-coccous. 
The cocci are subspherical and have, when ripe, a dull green, sparingly 
setose, thinly coriaceous pericarp which opens loculicidally so as partially to 
expose the seed. The seed, which is almost globose, is completely enveloped 
in a bright scarlet arillus, organically quite free from the hard, crustaceous, 
nearly black, rugosely foveolate-reticulate testa. The albumen is fleshy, 
the conspicuous axile embryo has a conical radicle with two flat, expanded, 
suborbicular cotyledons. The coriaceous valves of the cocci remain long 
attached to the flat, subspathulate, flexible columella which is tipped by the 
marcescent stigmas; often the valves fall away before the seeds become 
detached. The accounts hitherto given of the fruit of E. aaileata have 
been incomplete descriptions of the seed ; what has been termed a fleshy 
exocarp (Gen. Plant., iii. 308) or a thin sarcocarp (Engl. Bot. Jahrb., xix. 
89) is the arillus, the crustaceous endocarp being the testa. We have 
seen that, although this is the only character on which Mueller relied in 
distinguishing Erythrococca from Claoxylon , it has not been used for this 
purpose by Pax. That author has, however, placed a certain amount of 
dependence upon the criterion in another connexion. An interesting plant 
collected in fruit by Pogge on the river Lulua, a tributary of the Congo, 
which has the perulate buds, the stipular thorns, and the plumosely laciniate 
stigmas of Erythrococca , has been treated by Pax as the type of a distinct 
genus Poggeophyton (Engl. Bot. Jahrb., xix. 88), partly because the glands 
which surround the base of the ovary differ from the hypogynous scales 
of E. aculeata , and partly because it has a dehiscent capsule. The fruit 
of Poggeophyton acuteatum , Pax, is, however, quite like that of Eiythrococca 
aculeata , Benth., and the only difference in the seeds of the two is that in 
Poggeophyton aculeatum the arillus does not completely envelop the testa. 
The necessity for treating Poggeophyton as a genus apart from Erythrococca 
therefore rests on a difference in the appearance and disposition of the 
component parts of the hypogynous ‘ disc' in the two plants. 
The two criteria employed by Pax in 1890 differ from the one relied 
upon by Mueller in 1866 in being real and not imaginary. As the staminal 
criterion is not looked upon by Pax as an absolute one, it is more con¬ 
venient to consider the two separately. In considering them it is, more¬ 
over, necessary to take into account the circumstances under which they 
1 This account is based on an examination of (<2) the original specimens of Adelia anomala , Juss., 
collected by Smeathman in Sierra Leone; ( 3 ) the original specimens of Erythrococca aculeata, 
Benth., collected by Vogel in Sierra Leone; (V) specimens of the same species collected by Scott 
Ellict in Sierra Leone. 
