178 
the neighbouring States of North America, which is said to be 
capable of supplying rubber of fair quality and in large quantities 
should it ever be needed to supplement that of Hevea brasiliensis. 
Taxonomic Posrrion. Systematically this tree occupies a 
somewhat isolated position. It is the sole member of the genus, 
Eucommia, which the late Prof. Oliver established for its recep- 
tion. 
From material supplied by Prof. Henry, Oliver* described 
the plant in 1890 and named it Hucommia ulmoides. In a 
further papery he refers to the sdeeiey of his Hucommia ulmoides 
with Baillon’s Euptelea Davideana, on the authority of Baillont 
himself, but this identification was not justified, the two plants 
belonging to quite different genera§. He points out that though 
the nearest ally of Hucommia would appear to be Euptelea, it 
differs quite sufficiently to warrant the creation of a new genus 
for its reception. e further considers that there can be now 
no reasonable ground for hesitation in separating this genus, 
Eucommia, along with Cercidiphyllum, Euptelea, Trochodendron 
and Tetracentron, from the Magnoliaceae, and in placing them 
in a distinct family. He agrees to adopt Prantl’s name, 
Trochodendraceae, for this new family, which differs chiefly 
from the true Magnoliaceae in having naked flowers (no perianth) 
and in being without oil glands. He lays stress on two features 
possessed by Hucommia, viz., solitary ovary with bifid stigma 
and caoutchouc-containing cells, which serve to distinguish it 
from Huptelea. As regards the first-mentioned feature, it may 
be asked: Are we to infer that the flower of Eucommia possesses 
a single carpel only, or that it has really a synearpous dicarpellary 
gynoecium? If the latter inference be correct, then Hucommia 
would seem to be still less related to Huptelea ; in fact its inclusion 
in the T'rochodendraceae would be hardly warranted. 
It is not the intention here to discuss fully the systematic 
position of this interesting tree, but it may be pointed out that 
Solereder'| from his investigation of the female flower considered 
it syncarpous and dicarpellary, and was inclined consequently 
to place the plant in the Hamamelidaceae. Van Tieghem{ like- 
wise did not regard it as belonging to the T'rochodendraceae, and 
to emphasize its isolated position, made a new family, the 
Eucommiaceae, for its reception. Engler agrees with this view, 
for in the latest edition of his Syllabus der Pflanzenfamilien (1919) 
the family, Eucommiaceae, occurs and is put in the cohort, 
Rosales, next to the Hamamelidaceae. 
* Oliver, D. 1.c. 
+ Oliver, D. Hooker’s Icon. Plant., xxiv., 1895, t. 2361. 
ft See <a from Baillon sy Oliver in Herb. Kew 
msley in Hook. Icon. Pl. in syn. sub t. 2787. 
|| Solere eink r, H. Ber. Douts ch. Bot. Gesell., xvii., 1899, p. 387. In 
this oe — author ace es 7 of Euptelea Davideana Baill. 
with Euc ia ulmoides, Oliv considers it rather to be identical 
with eaniot spleticiaiaaa Hoo kf. ‘et Th oms. [This opinion was confirme: ed 
by gaia l.e.—Ed.] 
m, van P., Journ. de Bot., xiv., 1900, p. 262; see also 
Mr. Pees, ee s paper on Winteraceae, p. 185 of this number. 
