576 



PART JII. THE CLASSIFICATION OF PLANTS. 



Cohort I. Piperales. The flowers are usually ambisporangiate, 

 and they are arranged in a spike or a spadix, with bracts ; perianth 

 usually absent. Ovary usually superior, nionomerous or trimerous, 

 unilocular. Ovule orthotropous, solitary, basal or suspended ; in 

 some cases there are several parietal ovules. The embryo is small 

 and lies imbedded in endosperm, usually in a depression of the 

 abundant perisperm (Fig. 295 B, p. 458). 



Order 1. PIPERACK^E. Ovary superior, usually trimerous or 

 monomerous, unilocular, with a single orthotropous, erect, central 

 ovule. The inflorescence is a long spadix, 

 with usually peltate subtending bracts 

 (Fig. 376 /, below), in the axils of which 

 the flowers are situated. The flower con- 

 sists only of a ovary (Fig. 376 /, above) 

 and generally six, three, or sometimes two 

 stamens ; the fruit is a berry. 



FIG. 376. Part of the spa- 

 dix of Peperomia, with a 

 flower : / (below) the sub- 

 tending bract ; s s the two 

 stamens ; / (above) ovary ; fc 

 surface of the spadix (mag.). 



Piper nigrnm is a climbing shrub belonging to 

 the East Indies ; the unripe dried fruits are black, 

 pepper ; white pepper consists of the ripe fruits 

 of the same plant, which, after maceration, are 

 freed from their outer coat. Cubebs are the fruits 

 of Piper Cubeba of Java. 



Order 2. CHLORANTHACE.E. Flowers 

 sometimes with a rudimentary perianth. Ovary inferior, mono- 

 merous, with a single suspended ovule. Seed with oily endosperm, 

 but no perisperm. Tropical or sub-tropical. 



Order 3. SAURURACE^. Flowers without perianth. Gynseceum 

 of three or four carpels, either apocarpous or syricarpous : in the 

 former case each ovary bears 2-4 orthotropous ovules on its ventral 

 suture (marginal placentation) ; in the latter case the unilocular 

 ovary bears 6-10 ovules on each parietal placenta ; ovary superior. 

 Seed as in Piperaceae. Herbs with a rhizome, belonging to North 

 America and Eastern Asia. 



Houttuynia cordata (see p. 48) is a common weed in Japan and China. 



Cohort II. Urticales. Flowers usually diclinous, in inflor- 

 escences of various forms : perianth usually present, simple, 

 sepaloid, consisting tYBJgally of five () or reduced to four (2 + 2) 

 segments; stamens equal in number and opposite to the segments 

 of the perianth, in consequence, apparently, of the essentially 

 spiral arrangement of the floral organs (see p. 497) ; ovary 



