278 MOXOCOTYLEDONES. 



5. LILITFLOR.E. These advance from forms with the typical diagram and 

 bypogynous flower, to epigynous and reduced forms. 



6. SciTAiiiNE.E and 



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

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

 duced forms. 



Family 1. Helobieae. 



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 order-s 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 maybe 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 (Hydrocharitacete) 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 

 Juncaginacea 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, through the peculiar Zosteretc, 

 appears to approach the Aracea?, in which Potamogetonacece and Najadacece are 

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

 it Ruppia and Zannichcllui, in the Juncaginacea? appears quite correct. It would 

 scarcely be right to separate Zo<t?re(e from these. Great stress has often been 

 laid upon the similarity with the B-muuculacea? which is found in the Alismacea?, 

 but it is scarcely more than an analogous resemblance. 



Order 1. Juncaginaceae. The $, regular, liypogijnous 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 (" squamula3 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. 



