11^ JOURNAL OF THE ARNOLD ARBORETUM [vol. i 



The Calpidia, or Pisonia as it was formerly called, is in bulk the biggest 

 tree now on tlie Bonlns being often 8 meters in girth of trunk and from 

 20 to 25 m. tall. The bark is smooth, gray and the branches massive and 

 well clothed with large dark green leaves, but llie wood, altliough fibrous, 

 is brittle, soft and al)solutely useless. It is everywhere common but the 

 largest trees are found only on Sekimonzan in TTaha-jima. 



With six species, all endemic, Lauraceae is the family richest in trees but 

 they are all of small size and, except the Cinnamomum, of no particular 

 value. The Cinnamomum was called by the Bonin Islanders ** Sassafras,'* 

 and among the published correspondence of Nathaniel Savory are many 

 references to this tree, especially from his acquaintances down on the island 

 of Guam who often ask for ''Sassafras bark and seed." Another name for 

 it was "Tea Tree" and its wood was used for making hulls of canoes. I am 

 a little sceptical about Koidzumi's Machilus pseuJokobu being distinct from 

 Maximowlcz's species, but my material is insufficient, ^fy visit was not a 

 seasonable one for Lauraceae, as fruiting material is so necessary for de- 

 termination in this family. 



The Distylium is more often a bush than a tree and the same is true of 

 the Photinia and Raphiolepis. The last named furnished the wood for 

 making tool-handles, being both tough and strcmg and not too heavy. It 

 was first known as *' Axe-handle-wood" and then as illiteracy became more 

 general it became "Areki-san-doru" and finally "Sandal-wood," and as such 

 is mentioned by Robertson. This small tree is common everywhere and its 

 bloomy black, globose fruit in upright clusters are most handsome. I pre- 

 fer to keep it as a species under Hooker & Arnott's name than to refer it 

 as a variety to the variable Japanese li, umhcUafa ^Nlakino, more generally 

 known under Siebold and Zuccarini's name of R. japoiika. 



The Boninia as the sole endemic genus Is interesting. More often a large 

 bush than a tree, yet it is sometimes 10 meters tall with a trunk 0.6 m. in 

 girth, clothed with smooth gray bark; the leaves are persistent, variable in 

 size, usually shining, but often dull, green. It is dioecious and the small 

 white flowers are borne in axillary cymose clusters; the fruit is capsular. It 

 is everywhere abundant and is often used as a hedge plant. Planchon 

 (in Ann, Set. Nat, ser. 5, xiv. 310 [1872], founded the genus on material 

 from Herb. Acad. Petrop. and in Herb. Hook. no. 56, and distinguishes two 

 species (Boninia grii>ca and Boninia glabra) on trivial characters. Koidzumi 

 (in Tokyo Bat. Mag, xxxi. 200 [1917]) reduces them to one species {B. 

 glabra) and rightly so, I think, though he is in error in citing them as noniina 

 nuda. The other Rutaceous tree here described as a new variety of Zan- 

 thoxyluni ailanthoidcs Sieb. & Zucc. was known to the Bonin Islanders by 

 the sinister name of "Poison Tree." It is very common, but the only large 

 trees I saw grew on Mulberry Mt. and were 20 meters tall and from 2 to 

 2.5 meters in girth of trunk. The bark is smooth, pale gray, and the pin- 

 nate leaves are 0.8 meters long. It has not the prickles found on the 

 Japanese type with which it has been confused. 



The Claoxylum is a recently described species and is a slender tree con- 



