186 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. X, NO. 6. 



and are provided with green blades, but onlv the first one of these, L 1 , alternates with the 

 membranaceous; the four succeeding are turned 90° to the side (L 2 -L 5 ), and we noticed, fur- 

 thermore, that the two outermost (L 2 and L 3 ) were united at the base, forming a closed sheath 

 around the inner ones. Wh-ile thus the leaves described above are arranged alternately, but 

 in two planes, the succeeding (6-13) represent a spiral and surround the terminal inflorescence. 

 The numerous flowers are almost sessile and are destitute of bracts and fore-leaves; the central 

 is the first one to bloom, and judging from the rudimentary stage of the peripheral flower-buds 

 the time of flowering must extend to several months with onlv a few (two ?) flowers developed 

 at the same time. 



While thus the subterranean stem-portion of Weldenia often possesses a few stretched inter- 

 nodes, the aerial shoot is merely represented by a dense rosette of green leaves surrounding the 

 sessile many-flowered inflorescence, which is of the centrifugal type. 



The Internal Structure of the Vegetative Organs. 



the roots. 



Most of the roots are thick and fusiform, but some few thin and cylindric ones were also 

 observed. These slender roots were developed at the base of the dormant buds, and they show 

 the structure as follows: The thinwalled and hairy epidermis covers an exodermis of two la} T ers, 

 of which the cellwalls are not contractile. The cortex consists of ten layers; the cells are very 

 thinwalled and are arranged radially toward the endodermis. Deposits of starch were observed 

 in the innermost strata of the cortical parenchyma. Endodermis is thinwalled and shows the 

 Casparyan spots very plainly. The pericambium is thinwalled and continuous; it surrounds nine 

 broad groups of leptome alternating with nine very short rays of hadrome, which consist of one 

 or, seldom, two spiral proto-hadrome vessels and a single, wide, scalariform inside. A thinwalled 

 pith without starch occupies the greater part of the central cylinder. No raphides or crystals 

 were observed. 



The fusiform roots consist of a short, slender base, a long tuberous portion, that averages 

 from 4 to 7 centimeters in length and 6 to 10 millimeters in thickness, and finally of a long, 

 slender apex. 



The slender, basal portion of these fusiform roots is hairy and the exodermis is contractile. 

 The cortical parenchyma is composed of numerous layers, but only the three innermost are 

 preserved and contain starch; the others are collapsed. Endodermis is thinwalled and shows 

 prominent tangential foldings; the pericambium is also thinwalled and continuous. In regard 

 to the leptome and hadrome we noticed the same structure as described above, but the number of 

 rays is larger, there being 21, alternating with a corresponding number of leptomatic strands. 

 The thinwalled pith represents a broad parench} T ma containing starch. 



In passing to describe the swollen portion of these same roots, we might state at once that 

 the structure in general is identical with that of the slender base; the larger dimensions depend 

 merely upon a larger size of the cells in the cortical parenchyma and in the pith, while the number 

 of strata is the same. The cortex is, moreover, solid in this portion of the root, and not collapsed. 

 In the slender apical portion of these same roots the structure is almost the same. However the 

 exodermis showed no foldings of the cell-walls; the cortex consisted of only 12 layers filled with 

 starch; the number of hadromatic rays was only 12, and the pith represented a smaller parenchyma. 



In regard to the proto-leptome cells the accompanying drawings (PI. VIII, figs. 50 and 51) 

 illustrate two cases from the swollen portion of these roots. The leptomatic groups are some- 

 times very broad, and in such cases it appears as if two proto-leptome cells were developed 

 instead of but one, when the groups are narrower. 



the rhizome. 



One of the basal stretched internodes shows the following structure. It is cylindric, with a 

 shallow and narrow groove on the one side. The cuticle is thin and smooth, and covers a thin- 

 walled epidermis of small cells; viewed en face the cells are narrow and rectangular. A few 



