406 RUSSELL— A COIMPARATIVE STUDY OF 



of the Allegheny Mountains. The indications are that it is not found 

 on the more recent areas which have become the coastal plains. Stone's 

 Flora of New Jersey (17) records no locality for Floerkea proserpinacoides. 



Morphological and Anatomical Study of Floerkea and Limnanthes 

 Besides the close relation of the two genera, Limnanthes and Floerkea, 

 as shown by their distribution, there is an even closer relation revealed 

 by their structural similarities. This will be shown immediately in the 

 discussion of the two forms Limnanthes Douglasii and Floerkea proser- 

 pinacoides, representative of the two genera. 



Gennination 



Floerkea proserpinacoides shows hypogeal cotyledons and Limnanthes 

 Douglasii shows epigeal cotyledons. The cotyledons are in both ovate 

 and thick. Those of Limnanthes Douglasii are peculiar in that they 

 possess at their tips a very noticeable water stomatic area as is the case 

 in the leaflets. The cotyledons are green, functioning as leaves, and the 

 presence of the water stomatic area on the leaf is not surprising since its 

 habitat is usually an extremely moist locality (Fig. 1). 



In Floerkea, a longitudinal section of the cotyledon shows at the tip, 

 in the region corresponding to that of the water stomatic area in Limnan- 

 thes Douglasii, a distinct mass of epithem tissue (Fig. 2). This area 

 can scarcely be considered to function as a water stomatic area in such 

 colorless subterranean cotyledons. Rather it might be regarded as a 

 vestigial structure. Its presence, however, is valuable as an indication 

 of an ancestry of plants possessing epigeal cotyledons equipped with a 

 water stomatic area at the tip as already traced in Limnanthes Douglasii. 



This distinction between Limnanthes and Floerkea may possibly be 

 broken down by the finding of a series ranging from epigeal through semi- 

 hypogeal to hypogeal in the relation of their cotyledons. It may be that 

 a reduced form, such as Limnanthes Macounii, might present this transi- 

 tion condition. No material for actual observation was obtainable and 

 no references relating to the cotyledons were found. 



Floerkea proserpinacoides this year (1917) germinated in the regions 

 about Philadelphia in the week of March 21-28. By March 28, the plants 

 were showing their first leaf in most locaUties. By the foUowdng week, 

 the petiole of the first leaf had lengthened enormously. The second leaf 

 was beginning to unfold and the flower buds were visible in the axils of 

 the unfolding leaves. The first flowers appeared from April 9th on. 

 The flowers are produced through April, one arising from the axil of each 

 successive leaf. The present was an exceptional year for Floerkea. 



