FLOERKEA PROSERPIN ACOIDES AND ALLIES 407 



From the end of April to the first week in May, it is usually dying out, 

 and the seeds are ripening. This spring has, however, been extremely 

 backward and now (May 25-29) the flowers are still appearing. The 

 fruits formed from the earlier flowers are still green. The plants are 

 beginning to show signs of decay, however. The leaves and stems are 

 becoming withered and yellow. A few days of warm weather will 

 probably end the unusually long period of growth of Floerkea proser- 

 pinacoides for this year. 



The references made to the blooming season of Limnanthes indicate 

 that the height of the blossoming period corresponds to that of Floerkea. 

 April is the time for the appearance of the showy flowered Limnanthes 

 in the western states. 



Root 



The root system of Floerkea proserpinacoides is characteristic of a 

 shortlived reduced umbrophyte, that is, it consists of a few short fibrous 

 unbranched roots. Besides the normal roots, adventitious roots may 

 appear at the nodes on the stem, especially when the stem is procum- 

 bent upon the moist earth. These adventitious roots do not often appear 

 above the third node. Plants growing upright in habitats more umbro- 

 phytic than hydrophytic do not show adventitious roots. 



Limnanthes Douglasii shows a similar adventitious root formation at 

 the first or second node. 



In order to study microscopically the structure of the root in Floerkea 

 proserpinacoides and Limnanthes Douglasii, material was imbedded in 

 paraffin and sectioned. All sections were double stained with safranin 

 and Delafield's haematoxylin unless other%\'ise stated. 



A transverse section of a mature root of Floerkea proserpinacoides 

 thus prepared (Fig. 3) showed : Externally a bounding layer of rounded 

 epidermal cells, cuticularized externally. Within the epidermis is a 

 homogeneous cortical region three to four layers in depth, composed of 

 large round cells with thin walls. The innermost cortical layer is dif- 

 ferentiated into a well-marked endodermis of elliptical cells thickened 

 upon their inner and lateral faces. Within the endodermis is the peri- 

 cambium, a single layer of large thin-walled cells This layer forms the 

 outermost part of the vascular strand. The stele consists of a simple 

 diarch bundle. The xylem plate is uniseriate, being formed of two to 

 three spiral tracheae at each end, and three to four spirally thickened 

 vessels centrally placed. The two phloem masses are of small thin- walled 

 cells, not separable into the various phloem elements. 



