278 MONOCOTYLEDONES. 



5. LILIIFLOBJE. These advance from forms with the typical diagram and 

 hypogynous flower, to epigynous and reduced forms. 



6. SCITAMINE^E and 



7. GYNANDR.E. Two isolated families, which probably have taken their ori- 

 gin from Liliiflorae, and have epigynous, mostly zygomorphic, and much re- 

 duced forms. 



Family 1. Helobiese. 



To this family belong only water- or marsh-plants ; the endosperm 

 is wanting, and they possess an embryo with a very large hypocotyl 

 prolonged downwards and often club-like. The perianth is often 

 differentiated into calyx and corolla ; the flower is regular, and in 

 the first orders to be considered, may.be reduced to the ordinary 

 Monocotyledonous type ; there are, however, usually found two 

 3-merous whorls of carpels (Fig. 282), and' thus in all 6 whorls, 

 or again, the number of carpels may be indefinite ; the number of 

 stamens also may be increased, either by the division of the 

 members of a whorl, or by the development of additional whorls. 

 Syncarps, 1 with nut or follicular fruitlets, are very common, for 

 example, in the first orders ; in the last (Hydrocharitaceae) the 

 carpels are not only united, but the ovary is even inferior. 



The primitive type appears to be a hypogynous flower, similar to that of the 

 Juncaginaceae or Alismaceas, with several 3-merous whorls, and free carpels, 

 each with many ovules 'the green perianth in this instance being no doubt older 

 than the coloured ones. If we take a flower with this structure as the start- 

 ing point, then the family dcvelopes partly into epigynous forms, partly into 

 others which are so strongly reduced and exceptional that it is scarcely possible 

 to refer them to the ordinary type. The family, tbrough the peculiar Zosterece, 

 appears to approach the Araceae, in which Potamogetonaccce and Najadacets are 

 included by some authorities. However, the inclusion of Potamogeton, and with 

 it liuppia and Zannichellia, in the Juncaginaceaa appears quite correct. It would 

 scarcely be right to separate Zosterece from these. Great stress has often been 

 laid upon the similarity with the Ranunculaceae which is found in the Alismaceae, 

 but it is scarcely more than an analogous resemblance. 



Order 1. Juncaginaceae. The , regular, hypogynous flowers 

 have the perianth 3 + 3, sepaloid, stamens 3 + 3 (with extrorse an- 

 thers), and carpels 3 + 3 (free or united), of which last, however, 

 one whorl may be suppressed (in Triglochin maritima all 6 carpels 

 are developed, in T.palustris the inner whorl is unfertile). Inflores- 

 cence long spikes. Embryo straight. Marsh-plants with radical, 

 rush-like leaves, arranged in two rows, and often sheathing and 

 ligulate (" squamulge intravaginales ") ; the inflorescence is a spike 

 or raceme. Scheuchzeria. Carpels almost free ; in each at least 

 1 Syncarp = cluster of fruits belonging to one flower. 



