44 SEEDS AIs^D PLANTS IMPORTED. 



53262. OcHROMA LAGOPUS Swartz. Bombacacese, Balsa. 



From Camaguey, Cuba. Seeds presented by John R. Johnson, through Dr. 

 R. L. Luaces, director, Granja Escuela. Received May 9, 1921. 



" I believe that this tree will produce very well at Miami, for the flowers 

 form during March." (Luaces.) 



A West Indian tree 18 meters high with brown tomentose to nearly glabrous, 

 obscurely 3 to 5 lobed leaves 15 to 20 centimeters long, and yellowish white 

 flowers 10 centimeters long. The utilization of the wood of Ochroma has 

 brought that genus into prominence during the last few years. The manufac- 

 ture of buoyancy and insulation products, such as life rafts, refrigerators, and 

 parts of lifeboats and airplanes, especially in connection with the war, has 

 become very extensive. Eighty thousand floats made of balsa wood were 

 used in constructing the 2.50-mile submarine mine barrage in the North Sea : 

 war vessels as well as transports were in so far as possible equipped with 

 balsa life rafts and lifeboats ; and special refrigerating trucks with balsa as the 

 insulating material were used in France. The wood of the trees of this genus 

 is the most notable among light-weight wootls. It is generally known in Span- 

 ish America as " balsa," and that word has l)een transferred to and is in 

 general use in the United States. Balsa is the Spanish word for raft, and it 

 was applied to this tree because the Spanish colonists, when they migrated to 

 the New World, found it in use by the natives for rafts. 



Balsa is a very common and con.spicupus tree in tropical America. It is 

 distinguished not only by its light sofr wood, but also by its large simple 

 leaves, large solitary flowers, and very conspicuous fruit, which is not unlike 

 a cotton boll on a large scale. When the fruit is matured, hut has not finally 

 burst, it looks much like a rabbit's foot and presumably from this the first 

 species of Ochroma to be described received the specific name " lagopus." 

 When the fruit finally bursts and the mass of down falls to the earth, it 

 suggests the fur of a rabbit. The seeds are enveloped in this fur and are 

 disseminated by it. They resemble small grape seeds and, unlike cotton, the 

 " down " is not firmly and permanently attached to the seetl. 



The .species of this genus most frequently occur in the lowlands and foothills, 

 though rarely, if ever, where the soil is at all affected In- brackish or salt water. 

 They have not been discovered in the higher alt;tude.s. that is, at more than 

 1,000 meters above sea level. 



Balsa is usually a second-growth tree, though it does occur as an isolated 

 tree in the primeval forest. It appears promptly and abundantly where clear- 

 ings have been made by natural agencies, such as floods and fires, or by human 

 cultivations. In this respect it might properly be called a tree " weed." The 

 natural seeding in some places produces such an abundance of young plants as 

 to suggest weeds in a neglected garden. The tree's growth is very rapid. In 

 the natural state the wootl is very perishable. One rarely sees the remains of 

 trees of balsa in the tropical forests. They decay with apparently the same 

 rapidity as a cotton fabric ; the wood absorbs moisture readily and shrinks and 

 warps badly. This is due undoubtedly to the feeble lignification of the cell 

 walls and to the lack of aseptic properties such as the timber of oak and pine 

 possess. It was only when engineers, after protracted investigation and experi- 

 ments, overcame these defec-ts that the wood could be fabricated into valuable 

 products. (Adapted from Journal of the Wa^^hington Academy of Sciences, 

 vol. 9. p. 157.) 



For previous introduction, see S. P. I. No. 47593. 



53263 to 53266. Gossypium barbadexse L. Malvacese. Cotton. 



From Gizeh. Egypt. Seeds presented by T. Trought. botanist. Ministry 

 of Agriculture. Received May 4, 1921. Quoted notes by Mr. Trought. 



53263. "Ashnwuni, second grade, selected." 

 For previous introduction, see S. P .1. No. 7030. 



53264. '' Doiimains Assili." 53266. " Zagora." 



53265. " Doumains Sakel.'' 



