FLOERKEA PROSERPINACOIDES AND ALLIES 409 



phloem cells form a loose, open-celled outer bast fiber region. L. 

 Douglasii shows this more strongly developed. Between the phloem 

 and the xylem, there is an easily recognizable large celled intrafascicular 

 cambium. There is no interfascicular cambium shown however. The 

 intrafascicular cambium shows division to form secondary wood. In 

 most of the stems sectioned, 8 to 10 bundles were distinguishable. Sev- 

 eral join, usually two to four at the ends of the eUipse of the bundle 

 strand The bundles thus placed are those which pass off at the node 

 into the petioles of the leaves. The other bundles remain distinct. 



In the transverse sections of L. Douglasii stems which were cut free 

 hand from herbarium material, and stained in safranin and methyl 

 green, the structure was found to resemble F. proserpinacoides closely. 

 The epidermis is as in F. proserpitiMoides, excepting for the development 

 of a thick cuticle. The same regular row of cells is present immediately 

 beneath the epidermis. The cortex is of from 7 to 8 layers of large cells; 

 intercellular spaces are rare, no air lacunae are present. The endodermis 

 is indistinct. The bundles are more strongly developed, that is, the 

 xylem elements are more numerous, and the phloem patches are larger. 

 A complete ring of bundles is not formed, and little secondary wood is 

 laid down. The two outer layers of the phloem form a poorly developed 

 bast fiber region. The cambium is pecuUar, its large thin-walled cells 

 resembling markedly the cambium in F. proserpinacoides. The young 

 stem of L. Douglasii, above the cotyledons, shows a number of 

 air lacunae in the cortex corresponding to those in F. proserpinacoides. 

 These do not appear in the older stems of L. Douglasii examined. 



The bundles vary in number, in the stem of F. proserpinacoides, 

 according to the level at which the sections were made. In the younger 

 parts of the stem, the bundles may be four with four wide medullary 

 rays between the bundles. This is also true in L. Douglasii. These 

 bimdles separate in the older stem into a number of bundles. At the nodes 

 four bundles give off traces into the petiole. 



Leaf 



The leaves in F. proserpinacoides are alternate, exstipulate, and 

 pinnately compound, with 3 to 5 leaflets. In Limnanthes, the leaves 

 may be pinnate wdth 7 leaflets, to bipirmate as in L. Douglasii. 



The first foHage leaf is trifoliate. The second leaf may be perfectly 

 5 foliate, but is more usually imperfectly divided, showing one terminal 

 entire leaflet, and two lateral half-divided leaflets, or four entire leaflets. 

 The third leaf is usually perfectly 5 -foliate in Floerkea. 



