308 



MONOCOTYLEDONES. 



Family 4. Enantioblastse. 



The flowers in this family are hypogynous and have in part the 

 general monocotyledonous type with 5 trimerous whorls completely 

 developed in a regular hermaphrodite flower, and in part the 

 flowers so much reduced that the type is very difficult to trace. 

 On the one hand the family is well developed and has capitate 

 inflorescences (Eriocaulacece) and on the other hand it is distinctly 

 reduced (Centrolepidacece) . This family has taken its name from 

 the fact that the ovule is not, as in the Liliifloras and nearly all 

 other Monocotyledons, anatropous, but orthotropous, so that the 

 embryo (ftXa-a-rrf) becomes placed at the end of the seed opposite 

 (evavrtbs) to the hilum. Large, mealy endosperm. The orders 

 belonging to this family are by certain authors grouped with the 

 Bromeliacece and Pontederiacece, etc., into one family, FARINOSE, 

 so named on account of the mealy endosperm, the distinguishing 

 character of the Liliifloros then being that the endosperm is fleshy 

 and horny. 



Order 1. Commelinaceae. The complete Liliaceous structure without great 

 reductions in the number of whorls, but with generally few ovules in each 

 loculus of the ovary, is found in the CommelinaceEe, an almost exclusively 

 tropical order with about 317 species ; herbs, some of which are introduced into 

 our gardens and greenhouses. The stems are nodose ; the leaves often clasp- 

 ing ; the flowers are arranged in unipared scorpioid cymes, often so that they 

 form a zig-zag series falling in the median line of the bracts, and after flowering 

 they bend regularly to the right or left, outwards or inwards. They are more or 

 less zt/gomorphic, particularly in the stamens, which in the same flower are of 

 different forms or partially suppressed. The outer series of the perianth is 

 sepaloid, the inner petaloid, generally violet or blue ; the filaments are some- 

 times clothed with hairs formed of rows of bead-like cells (well known for 

 showing protoplasmic movements). Fruit a trilocular capsule with loculicidal 

 dehiscence (generally few-seeded) ; in some a nut. The radicle is covered by 

 an external, warty, projecting covering which is cast off on germination. 

 The abundant rapliides lie in elongated cells whose transverse walls they 

 perforate. Commelina, Tradtscantia, Tinnantia, Cyanotis, Dichorisandra. 



Order 2. Mayacaceae. This order is closely allied to the Commelinaceae. 

 7 species. American marsh- or water-plants. 



In many of the following orders of this family the flowers are united into 

 compound inflorescences, with which is accompanied a reduction in the flower. 



Order 3. Xyridaceae (50 species). Marsh-plants with radical, often equit- 

 ant leaves arranged in 2 rows, and short spikes on long (twisted) stalks. The 

 flowers, as in the Commelinacere, have sepals (which however are more chaffy) 

 and petals, but the outer series of stamens is wanting. Capsule (generally 

 many-seeded). 



Order 4. Rapateacese. Marsh-plants with radical leaves, usually in two 



