185 
figures and remarks of the former in Ann. Mus. 16. 449., and of the latter in 
Humboldt and Bonpl. N. Gen. et Sp. 1. 3.; the latter being unquestionably 
wrong in considering the sac a portion of the embryo. Tliis order is one 
of those which tend to destroy the distinction between Monocotyledons and 
Dicotyledons. Its affinity with Fluviales is indicated by the floating habit 
and general appearance of Aponogeton, and with Typhacese by its anthers ; 
but its foliage and stipules are those of Dicotyledons, and the structure of the 
seed and the position of the embryo in a fles% sac demonstrate its vicinity to 
Piperacese. 
Geography. Natives of North America, China, the north of India, and 
the Cape of Good Hope, growing in marshes or pools of water. 
Properties. Unknown. 
GENERA. 
Houttuynia, Thunb. Saururus, L, 
Polycarpa, Lour. Spathium, Lour. 
Aponogeton, Thunb. 
Order CXXXV. PIPERACE^E. The Pepper Tribe. 
PiPERACEiE, Rich, in Humb. Bonpl. et Kunth N. G. et Sp. PI. 1. 39. t. 3. (1815) ; 
Meyer de Houttuynia atque Saurureis, (1827). 
Essential Character. — Flowers naked, hermaphrodite, with a bract on the outside. 
Stamens definite or indefinite, arranged on one side or all round the ovary, to which they 
adhere more or less; anthers 1- or 2-celled, with or without a fleshy connective ; pollen 
smooth. Ovary superior, simple, 1 -celled, containing a single erect ovule; stigma sessile, 
j simple, rather oblique. Fruit superior, somewhat fleshy, indehiscent, 1 -celled, 1 -seeded. 
Seed erect, with the embryo lying in a fleshy sac placed at that end of the seed which is 
opposite the hilum, on the outside of the albumen. — Shrubs or herbaceous plants. Leaves 
opposite, verticillate, or alternate in consequence of the abortion of one of the pair of 
i leaves, without stipules. Flowers usually sessile, sometimes pedicellate, in spikes which 
i are either terminal, or axillary, or opposite the leaves. 
Affinities. As we approach the Monocotyledonous division of vegeta- 
bles, we find the distinction between them and Dicotyledons, as derived from 
their anatomical structure, becoming weaker and weaker ; but at the same time 
it appears to me that sufficient distinctions are still visible between these two 
modes of growth. Of this Piperacese are an instance. According to Richard, 
they are Monocotyledonous ; an opinion in which Blume concurs, after 
an examination of abundance of species in their native place of growth. See 
Ann. des Sc. 12. 222. But if the medullary rays constitute the great anatomi- 
cal difference between these divisions of the vegetable kingdom (and I know 
of no other which is absolute), then Piperacese are surely Dicotyledonous, as is 
shewn by Meyer {Dissertatio de Houttuynia, 38) and as may be ascertained by 
any one who will look at an old stem of any Pepper ; add to this, the veins of 
their leaves having a distinct articulation with the stem, and the 2-lobed em- 
bryo ; and it seems to me impossible to doubt their being properly stationed 
among Dicotyledons. In this view they are closely related to Polygonacese, 
Saururacese, and Urticacese, from all which, however, they are distinguished 
by obvious characters ; and also to Chloranthacese, from which they diff’er in 
the point of attachment of the ovule, and in the distinct existence of the remains 
of the amnios in the form of a sac around the embryo. In the opinion of those 
I who believe Piperacese to be Monocotyledons, their station is near Aracese, with 
