176 BOTANICAL GAZETTE [MARCH 
The stem 
The largest rhizome of the Australian material measures 0.7 
cm. in diameter and 2.5 cm. in length. There are 18 leaves still 
attached and the bases of 5 others are evident. All the rhizomes, 
with the exception of the very youngest, give evidence of having 
grown in a horizontal position; field observations by Dr. CHAMBER- 
LAIN confirm this. The leaf bases, however, are not restricted to 
the dorsal side, as stated by CAMPBELL (3) for this species, but are 
attached in a spiral about the stem. The distribution is irregular; 
on young stems the leaves are rather crowded and attached along 
a spiral with about a 4 arrangement. On older stems the distri- 
bution approximates a ? arrangement; fig. 6 shows the arrangement 
of the leaves on the largest specimen 
De ne secured. The bases of the leaves in- 
FE een s serted on the lower side curve round 
HEISE for ae ANN \ the rhizome and produce the appear- 
tot i Pie yeh ance of a 2-ranked arrangement, as 
BAA Seige P in Helminthostachys; but there is 
EN re ony nothing in the insertion of the leaves 
[eae ohare or the structure of the stem to indi- 
be ems cate true dorsiventrality. 
Fic. 6.—Diagram of leaf ar- The rhizomes of the Samoan ma- 
eae: . Se em tertal we decidedly larger than those 
from Australia; the oldest one 
secured, with 8 functional leaves and 7 leaf bases, was 1.2 cm. in 
diameter and 4.6 cm. in length. Both their appearance and their 
structure indicate a definite radial arrangement (fig. 5). The leaf 
insertion is similar to that of the Australian epee but the 
leaves are less crowded. 
All the rhizomes in which the bases are me give evidence of 
having developed from buds upon roots in the manner described 
above. The connection of the stem stele with that of the root was 
examined in 12 specimens; five methods of development of the 
stem stele were found. 
In a single specimen, a solid strand of xylem, surrounded by 
phloem and endodermis, separates at a considerable angle from one 
of the protoxylem strands of a tetrarch root (fig. 7). The endo- 
