168 FLORA INDIGA. [Menispermacca. 



Menispermacea constitute a very natural Order. The scandent habit, alternate, ex- 

 stipulate, palminerved leayes, petioles dilated and jointed at the base, minute, uni- 

 sexual, thalamiflorous (lowers, arranged in a ternary order, in at least three aud usually 

 four rows, and imbricated in fcstivatiou, the small scale-like petals, definite stamens, 

 definite apocarpous ovaries, solitary amphitropal ovules and fleshy drupes, charac- 

 terize all the typical species, and form a combination of characters which is to be 

 met with nowhere else. Of these the alternate exstipalate leaves, petioles not 

 sheathing at the base, minute thalamiflorous flowers, solitary ovules, and peculiar dru- 

 paceous fruit, are constant, but all the others are subject to exception. 



The scandent habit is almost universal in the Order, but it is absent in Cocculus 

 Jaurifotius^ which is a small, erect (or somewhat sarmentose) tree. 



The peculiar structure of the petiole so common in Menispermacece can only be 

 compared to that of a lew Euphoriiacea. The petiole is generally elongated and 

 cylindrical, without any marked groove in front, and has the appearance of being 

 articulated with the stem, but the leaves are seldom very deciduous. The joint is 

 sometimes a little above the base, so that a small projection is left on the branch 

 after the leaf falls away. Above the base, aud sometimes also near the leaf, the 

 petiole is generally thickened, but contracts suddenly. The thickened portion of the 

 petiole is often weaker in texture than the remainder, and exhibits a tendency to 

 that twisting which is characteristic of the petioles of Clematidea. In most spe- 

 cies of Cocculus the petiole is short, not dilated at either extremity, and scarcely 

 articulated. 



The leaves of Menispermacem vary much in shape and texture. The most com- 

 mon shape is broad cordate, or nearly round ; they are often peltate, but this mode 

 of attachment to the petiole is frequently present and absent in the same species, 

 and occurs at times in young individuals, even when absent in the adidt plant. 

 Many, however, have elongated leaves. The palmate arrangement of the nerves is 

 not confined to the peltate and broad cordate-leaved species, those vvith elongated 

 leaves being always three-nerved at the base. The leaves often present a great va- 

 riety of form, size, aud textare in the same individual, so that copious suites of spe- 

 cimens are necessary for the proper iUustration of each species. 



The flowers are almost always unisexual, but Mr. Micrs mentions the occurrence 

 of hermaphrodite flowers in Tiliacora- and Odoniocarya. In the female flower im- 

 perfect stamens are usually present, and in the male more or less distinct traces of 

 the gyncecium are usually found, except in the tribe Cissanipehdeie, and other mona- 

 delphous genera, in which the staminal column occupies the centre of the flower. 



The ternary arrangement of the parts of the perianth is of very general occurrence. 

 The most remarkable exception is met with in Jlr. Miers's genus Odontocarya, in 

 which he describes the calyx and corolla as forming each a single verticil of five leaves. 

 Odontocarya appears, however, from Mr. !Miers' analysis, to be a genuine Menisper- 

 maceous plant, the embryo having the laterally divaricating cotyledons of the tribe 

 Tinosporeco, In a part of the CissainpeVideo' the segments of the perianth are ar- 

 ranged in a binary (or more rarely quaternary) order, and in the same tribe they are 

 not unfrequently combined into a gamopetalous calyx and corolla. The solitary sepal 

 of Cissampelos (usually called petal) in the axil of the bract is evidently formed of 

 two combined sepals. 



The number nf verticils of the perianth is normally four, and they arc usually 

 sulBciently distinguishable into calyx and coroUa, (he latter being much the smallest, 

 so that the petals were often described by the older botanists as nectaries or scales. 

 Occasionally the petals are reduced to a single verticil of three, or entirely sup- 

 pressed i sometimes also the sepals are increased by the addition of one or more 

 verticils, or of a number of irregularly imbricated bracts. In Coscinium the petals 

 are larger than the sepals. 



The imbricated {estivation of the peiianth is not without exception, as in Tiliacora 

 and several Limacice the inner sepals are valvate. This has been pointed out in 

 Tiliacora by Mr. jMiers, and in Liinacia by Dr. Asa Gray. The petals of Coscinium 

 arc in like manner very slightly imbricated. 



