1291 



Acacia spherocephala (Mlmosaceae ) , 45792. Bull-horn 

 Acacia. From Zacuapam, Mexico. Presented by Dr. C. A. 

 Purpus . One of a group of acacias remarkable for 

 their large, stipular, inflated spines which closely 

 resemble the horns of a buffalo. This particular 

 species is a shrub or small tree. The leaves are bi- 

 pinnate, and have remarkable glands, rich in oil, on 

 the rachis and leaflets. The thorns are utilized by 

 certain stinging ants of the genus Pseudomyrna as nest- 

 ing places for their young. The thorns which are con- 

 nate at the base, are hollowed out by the insects, 

 which perforate one of the spines near the tip, so 

 that no water can enter. Belt suggests that in return 

 for quarters and subsistence on the minute wax-like 

 bodies on the leaflets, the little ants serve their 

 host as a body-guard of soldiers. Jacquin in describ- 

 ing a bullhorn acacia growing near Cartagena, (Colom- 

 bia) in 1763, tells how the little insects rush from 

 the thorns when the tree is struck however lightly, 

 falling upon the unv/ary intruder and inflicting upon 

 him myriads of burning stings. The flowers are borne 

 in globose heads 'on long thick peduncles, clustered 

 in the axils of the long forklike spines. The seeds 

 when ripe are surrounded by a sweetish yellow or 

 orange-colored pulp which causes the fallen pods to 

 be eagerly sought after by pigs and other animals. 

 (Adapted from Safford in Bailey's Standard Cyclopedia 

 of Horticulture, p. 598.) 



Cephaelis sp. (Rubiaceae), 45730. Raicilla or Ipecacuana. 



From Panama, R. P. Presented by Mr. Ramon Arias-Feraud. 

 "A small shrub belonging to the Rubiaceae, 8 to 16 

 inches high with ascending or erect simple stem and 

 somewhat creeping root. It is one of the sources of 

 the medicinal Ipecacuana. The typical plant grows in 

 Peru, but specimens of closely allied or identical 

 species from Central America are in the economic col- 

 lection of the United States Department of Agricul- 

 ture." (W. E. Safford.) 



Chenopodiitm sp. (Chenopodiaceae) , 45722. From 

 Mexico. Presented by Mrs. Zelia Nuttall , Casa Alvarado, 

 Coyoacan, Mexico City. "Native name, Tililhuauhtli, 'Black 

 huauhtli'. A plant used by the Mexicans as a potherb, 

 possibly the original form from which the pale-seeded 

 xochihuauhtli has been developed by cultivation. Like the 

 latter, the immature inflorescence ( huauhtzontli, or 

 huauhtli -heads ) is used for food. The seeds of this 



