398 Harper: Facrors INFLUENCING DISTRIBUTION 
becomes ‘“ Sonorized,’’ as several other species do, and is another 
thing. It is possible that 7. distichum intergrades with 7. mucro- 
natum as suggested by Professor Bray. The two species are 
scarcely distinguishable in the herbarium, the characters by which 
they are separated being mostly phaenological. Mr. Heller's 
specimens from Kerrville, Texas, seem to resemble the latter as 
much as they do the former, at least in their visible structural 
characters. 
One other point now remains to be considered, namely, the re- 
lation between Taxodium and Glyptostrobus. The latter genus was 
founded by Endlicher (Syn. Con. 69) in 1847, with two species, 
G. heterophyllus and G. pendulus, said to be natives of China. (He 
enumerates also in the same work three species of Taxodium.) 
In 1880 this genus was united with Zaxrodium by Bentham and 
Hooker (Gen. Pl. 3: 429). Eichler, in his treatment of the Coni- 
ferae in Engler and Prantl’s Natiirlichen Pflanzenfamilien, keeps 
the two genera apart, but considers the reasons for so doing scarcely 
sufficient. This subject has recently been more fully discussed by 
Dr. M. T. Masters,* who gives very good reasons for consid- 
ering the two genera distinct. I have seen only one specimen of 
Glyptostrobus (G. heterophyllus, in the Columbia University her- 
barium) myself, but its appearance suggests that its leafy branchlets 
might not fall off with the leaves as in the case of Jaxodium. 
This point is not mentioned by the authors just cited, and I have 
no means of verifying it at present. 
But the question of the identity of Zarodium and Gljple- 
strobus is not of such immediate interest to us as the relation 
of Taxodium imbricarium to Glyptostrobus pendulus. These were 
both mentioned by Endlicher in his Synopsis Coniferarum who 
seems to have had no suspicion of their similarity, but they have 
been regarded as identical by some authors, and this is probably 
the case. Professor Sargent treats them as identical in his Sylva 
of North America (10: 152. 1896), and in Garden and Forest 
(10: 451) for July 17, 1897, writes as follows: ‘“ The tree which 
in the United States and Europe is almost universally called Glyp- 
tostrobus pendulus, is really a juvenile [sic] form of the Jaxodium 
of the Southern States, G/yprostrobus being a south China gor 
* Jour. of Bot. 38: 37-40. Feb, 1900. 
