648 CONTEIBUTIONS FROM THE NATIONAL. HERBARIUM. 



24. SEBASTIANIA Spreng. Neu. Entd. 2: 118. 1821. 



Refebence: Pax in Engl. Pflanzenreich IV. 147'': 88-153. 1912. 



Trees or shrubs ; leaves alternate, petiolate, usually serrulate, with small 

 stipules; flowers usually monoecious, apetalous, spicate. 



Bracts of the inflorescence petiolate 1. S, adenophora. 



Bracts sessile 2. S. pavoniana. 



1. Sebastiania adenophora Pax & Hoffm. in Engl. Pflanzenreich IV. 147"': 145. 



1912. 

 Yucatan ; type from Silam. 



Shrub or tree, 3 to 6 meters high, glabrous; leaves ovate or oval-ovate, 3 

 to 5 cm. long, acute or acuminate, serrulate, slender-petiolate. " Kanchunup. " 

 This has been reported from Yucatiln as Excoecarla glandulosa Swartz. 



2. Sebastiania pavoniana Muell. Arg. in DC. Prodr. 15^: 1189. 1866. 

 Gymnantlics pavoniana Muell. Arg. Linnaea 32: 106. 1863. 

 Sebastiania pringlei S. Wats. Proc. Amer. Acad. 26: 149. 1891. 

 Sebastiania palmeri Rose, Contr. U. S. Nat. Herb. 1: 112. 1891. 

 Sebastiania ramirezii Maury, Naturaleza II. 2: 405. 1894. 

 Sonora to Tepic and San Luis Potosi. 



Shrub, 1.5 to 2.5 meters high, glabrous, with slender branches ; leaves lanceo- 

 late or ovate, 4 to 11 cm. long, acuminate, irregularly serrulate; slender- 

 petiolate; spikes slender, 1 to 3 cm. long; capsule about 1 cm. in diameter. 

 " Palo de la flecha," " hierba de la flecha " (Sonora) ; " mincapatli " (Nahuatl). 



The milky juice was employed formerly by the Indians for poisoning their 

 arrows. The best-knovv'n part of the plant, however, is the fruit, which fur- 

 nishes the famous " jumping beans " or " semillas brincadoras," which are a 

 common article in curio shops of the Southwest. The following is a translation 

 of the notes upon the subject published by Pax : 



" The jumping seeds have a curved outer side, with a rounded keel, and two 

 flat sides. They are yellowish gray and show on the outside no opening or 

 point of injury. If they are laid upon one of the flat sides, with a quick move- 

 ment they turn upon the other. A longer time is demanded for the movement 

 from the curved side to one of the flat ones. Frequently the beans hop several 

 millimeters in the air, and thus they may also move forvv-ard. 



" Soon after the first notice of these peculiar seeds it was conjectured that the 

 cause of the movement must be a living occupant, which was verified by investi- 

 gation. In the ' jumping beans ' lives the whitish larva of a small butterfly 

 belonging to the TortricMae, named by Westwood as Carpocapsa saltitans. The 

 insect occurs especially in the IMexican States of Sonora, MichoacSn, Guerrero, 

 Puebla, and Veracruz. The larva consumes tlie contents of the ' seed ' and 

 covers the inner surface of the latter with a web. The French entomologist 

 Lucas gives as an explanation of the jumping that the larva, which lacks much 

 of filling the cavity, supports itself upon the web by its body-feet, then loosens 

 its chest-feet and anterior body-feet, stretches itself out violently, and strikes 

 upon the wall of its dwelling with its head. 



" With a warm temperature the intensity of the movement increases, al- 

 though it is not brought to a halt by a lower temperature. Consequently the 

 seeds occasionally brought to Europe retain their movement for some time. In 

 Berlin the larvae survived for weeks in unheated rooms. Buchenau reports 

 that Martens in 1871 brought jumping seeds to Europe * * ♦. He had left 

 Mexico in the middle of June. There was no longer any food left in the seeds 

 for the larvae. Nevertheless their violent movements continued until March of 

 the following year. In April the larvae changed into chrysalises, and in May 

 or June the butterflies emerged, for which they lifted up a circular lid which 



