5^0 PHA NER GA MS. 



Sometimes however the outer perianth-whorl is green and sepaloid, the inner whorl 

 larger, delicate, and petaloid (Canna, Alisma, Tradescantia) ; in the very small and 

 closely crowded flowers of the Glumiflorse, the perianth-leaves, when present, take 

 the form of hairs (the setae of Cyperaceas) (Fig. 395), or of small membranous scales 

 (the pales and lodicules of Grasses). 



The Siameiis generally consist of a filiform filament and a quadrilocular anther ; 

 though variations frequently occur, especially in the form of the filament and 

 connective. Among the most striking deviations from the ordinary type are the 

 petaloid staminodes of Cannacese and Zingiberacese. It has already been pointed 

 out (pp. 426, 473), that the foliar nature of the stamens is subject to an exception 

 in the Naiadese (at least in Naias) according to the researches of Magnus, and in 

 Typha according to those of Rohrbach. The stamens of Monocotyledons scarcely 

 ever branch, as is often the case in Dicotyledons ; and this corresponds to the 

 customary absence of branching in the other foliar structures also. If the diagram 

 of the flower of Canna (Fig. 399), drawn according to Payer's description, is correct, 

 the petaloid staminodes are branched; according to Rohrbach the (axial) stamen 

 of Typha is also branched. 



The GyncBceum has usually a trilocular ovary; less often it is tricarpellary but 

 unilocular; in both cases it may be either superior or inferior, but the latter occurs 

 only in plants with large flowers (Hydrocharis, Irideae, Amaryllideae, Scitaminese, 

 Orchidere, &c.). The formation of three or more monocarpellary ovaries is limited 

 to the alliance of the Juncagineae and Alismaceae, in which the ordinary number 

 of members and of whorls of the gynseceum is also exceeded, reminding one of 

 the Polycarpas among Dicotyledons. 



Adhesion and displacement are not so common in the flower of Monocoty- 

 ledons, and usually not so complicated as among Dicotyledons ; among the most 

 striking phenomena of this nature are the formation of the gynostemium of Orchids ; 

 the cohesion of the six similar perianth-leaves into a tube in Hyacinthus, Con- 

 vallaria, Colchicum, &c. ; and the epipetalous and episepalous position of the 

 stamens in the same plants and in some others. Adhesion of the stamens to the 

 calyx or corolla occurs much less constantly in particular families among IMono- 

 cotyledons than among Dicotyledons. 



Terminal flowers to a leafy primary shoot occur very rarely among jMono- 

 cotyledons {e.g. in Tulipa) ; terminal inflorescences are more common. The flower 

 acquires a tendency to zygomorphism, especially as it increases in size ; but this is 

 often only feebly indicated, and attains its highest development in Scitamineae and 

 Orchideae. 



The Ovules of Monocotyledons usually spring from the margins of the carpels, 

 rarely from their inner surface (as in Butomus) ; the single orthotropous ovules of 

 Naias (according to Magnus) and Typha (Rohrbach) arise by the transformation of 

 the end of the floral axis itself (see p. 496) ; in Lemna and in some Aroideas one 

 or more ovules stand at the bottom of the cavity of the unilocular ovary. The 

 prevailing form of the ovule is anatropous ; but in Scitamineae, Gramineae, and some 

 other orders, campylotropous ovules occur; in the Enantioblastse and a few Aroideas 

 they are orthotropous, either erect or pendulous. The nucleus is almost without 

 exception enclosed in two envelopes (Crinum however forms an exception). 



