4 MR. R. SPRUCE ON THE MODE OF BRANCHING 



undescribed Myristicce — M. hypoleuca, Plant. Amaz. 3206, and M. 

 calophylla, PI. Am. 3207, found growing side by side on the 

 Casiquiare. Both species have the branches in whorls of five ; but 

 in the former the branches are bipinnate, and in the latter simply 

 pinnate, with large leaves, 16 inches long. A similar verticillate 

 ramification obtains in all the species of Myristica. Sometimes 

 two of the branches in each whorl are more slender than the other 

 three, as if later developed ; more rarely one or two members of 

 the whorl are absent. But in M. debilis, PI. Am. (Rio Uaupes), 

 an arbuscule from 3 to 10 feet high, and with a stem scarcely 

 thicker than the finger, the simple branches are placed in whorls 

 of three. This is the only instance of so extremely humble growth 

 among American Nutmegs, most of the species being timber-trees, 

 and some of them, such as M. fatua, Sw., and M. rugulosa, PI. 

 Am., reaching 80 or 100 feet in height. 



A very remarkable modification of the usual habit exists in a 

 Myristica observed (though not gathered) on the shores of the 

 Amazon, above the Rio Negro, in which the 5-nate branches are 

 abruptly bent upwards, about midway, into a nearly vertical direc- 

 tion. This is one of the very few trees on the Amazon which re- 

 main without leaves for a few weeks in the year ; and when I first 

 saw it (in July 1851), the naked branches had a very singular 

 appearance, more resembling pothooks than anything else ; but 

 when I ascended the Amazon to Peru (in March 1855), the tree 

 was in full foliage, and the view I obtained through my glass, of 

 the distichous coriaceous subligulate leaves, left no doubt on my 

 mind that it was a species of Myristica. Perhaps the peculiarity 

 in its ramification was produced by the branches flowering at the 

 apex (contrary to the habit of the other species) and emitting 

 an innovation, at nearly a right angle, from below the inflo- 

 rescence. 



What I saw in the Myristicce caused me to pay more attention 

 to the mode of branching in other trees ; but I encountered diffi- 

 culties in the prosecution of my observations, not easily appreciated 

 by those who have seen trees only in temperate climes. Except 

 near the banks of the rivers, it was rarely possible to ascertain 

 from beneath the mode of branching of any tree ; and when cut 

 down, the branches were often so crushed together, and so hidden 

 by the ruins of adjacent smaller trees, which were fastened by 

 stout lianas to the larger tree and had thus become involved in 

 its destruction, that it was impossible to trace their disposition, 

 especially as the ants, wasps, and snakes, set in angrj' motion by 



