190 
and leaves all confounded in one broad mass, or else with the latter decomposed into capil-' 
lary segments. 
The discovery of the genus Philocrene, which has three sepals, diminishes 
the probability of this alliance being rightly grouped, and the observations by 
Bongard, who considers the supposed sterile stamens of Podostemum to be in 
reality an imperfect calyx, induce me still more to suspect it should be stationed in 
the Rectembryose group near Lacistemaceae. Nevertheless I allow it to retain 
its present place until further infonnation can be had concerning the African 
portion of the order. If there is any type of structure more nearly approaching 
that of Asexual plants, or Acrogens, than any other, it must he surely this 
which with the habit of Marchantiaceae and Jungermanniaceae has so much 
he structure of flowering plants. According to Bongard, the species have neither 
spiral vessels, nor stomates ; the latter would of course be absent on account 
of the submersed habits of the species of Mourera to which his observations 
chiefly apply. 
Order CXLI. PODOSTEMACE.^. 
PodostemejE, Richard and Kunth in Humb. N. G. et Sp. 1. 246. (1815); Martins Nov. 
G. et Sp. 1. 6. (1822) ; Bartl, Ord. Nat. 72. (1830) ; Arnott in Edinh. Encycl. p. 
137. (1832) ; Bongard in Mem.de VAcad. Imp. Petersb. FI. ser. III. 69. (1834). 
Essential Character. — Flowers naked, or with a very imperfect calyx, or with 3 
sepals, hermaphrodite, bursting through an irregularly lacerated spathe. Stamens hypogy- 
nous, varying from 1 to an indefinite number, either placed all round the ovary or on one 
side of it, distinct or monadelphous ; anthers oblong, 2-celled, bursting longitudinally. 
Ovary 2- or 3-celled, with numerous ovules attached to a fleshy central placenta; styles or 
stigmas 2 or 3, and sessile. Fruit slightly pedicellate, ribbed, capsular, opening by 2 or 
3 valves, which fall off from the dissepiment, which is parallel with them. Seeds nume- 
rous, minute, according to Von Martins, entirely homogeneous ; but according to Bongard 
containing an exalbuminous dicotyledonous embryo. — Herbaceous branched floating plants 
[without stomates or spiral vessels. Bong.'] . Leaves capillary, or linear, or lacerated irre- 
gularly, or minute and densely imbricated, decurrent on the stem, with which they are 
not articulated. Flowers axillary or terminal, inconspicuous. 
Affinities. Von Martins has the following remarks upon this curious 
order. “ It is very doubtful in what part of the natural series Podostemese 
should be arranged ; for they are connected with so many other orders, in so 
various and complicated a manner, that it is highly probable that several 
genera, the affinities of which will be more apparent, still remain to be dis- 
covered. Nothing can be more singular than the mixture of different charac- 
ters which they exhibit. Thus, the stnicture of their spathes, and the want 
of a true calyx and corolla, approximate them to Naiades (Fluviales) and 
Araceae, while the character of their stamens and fruit is very much that of 
Juncaginacea? ; the former of these, however, differ in their lower degree of 
organisation, and the latter in the presence of a more or less perfect perianth, 
and in the composition of their capsule. Ijemna, a genus closely aUied to 
Aracese, seems to be more related to them in its spathe, h}T)ogynous stamens, 
habit, and mode of life, but is distinguished by its less highly developed few- 
seeded fruit. Again Mniopsis, in its ramification, in the form and position of 
its leaves, and in its stipules, and Lacis and Podostemum in the character of 
their spathe and the emersion of their pedicels at the time of flowering, caU 
remarkably to mind the habit of Jungermannise ; so that we should probably 
not be far from the truth, if we were to say that this order forms a transition 
from Naiades (Fluviales) to Juncaginaceae, on the one hand touching upon 
Araceae, thus being, as it were, a sort of noble analogy of Hepaticae among 
monocotyledons.” Nov. G. et Sp. 1. 7. Upon this it was difficult to make 
