360 TRANS. ST LOUIS ACAD. OF SCIENCE. 



species with really fleshy fruits. Huth* has a short note on R. 

 JFrangula in this connection, but I cannot place my hand on 

 observations upon our American species. The widely dehiscent 

 cocci of some species of Rhamnns pave the way for the elastic 

 dehiscence of those of Ceanothus and Coliibrina, in which the 

 fruit soon becomes dry and the seeds are expelled with consider- 

 able force.f The seeds of Gouania are rendered 2-winged by 

 the attached pericarp, each wing consisting of half of one of the 

 prominences originally developed over each septum. 



The seed-characters of Rhamnus ^ especially of R. infectoria^ 

 which furnishes a dye-stuft', have recently been discussed at length 

 by Marshall Wai'd, and Dunlop.J 



SYNOPSIS. 



Tribe I. Zizyphe.e. — Lobes of calyx deciduous (except in some species 

 of Condalia) ; disk lining the shallow cal_yx-tube, nearly or quite 

 free from the ovary; fruit mostly fleshy and edible, with a single i- 

 to 4-celled stone enclosing as many seeds or i-seeded by abortion. 



* Embryo relatively large ; albumen not ruminated. 



'*~ A single ovule to each carpel. 



■^ Apetalous, 



1. Condalia. — Style somewhat 2- or 3-lobed. 



"" ■" Petals present. 



2. ZizYPHUS. — Petals cucullate and clawed; style bifid, flowers um- 

 bellately clustered. 



3. MiCRORHAMNUs. — Petals cucullate and clawed ; style notched ; flow- 

 ers solitary; leaves minute, revolute to the broad midrib. 



4. Berchemia. — Petals clawless, acute, with incurved margins; style 



slightly 2-lobed. 



"*~ '*~ Two ovules to each carpel. 



5. Karwinskia.* — Petals cucullate, very short-clawed; style slightly 

 2- or 3-lobed. 



* * Embryo small in the center of copious ruminated albumen. 



6. Reynosia. — Apetalous; style somewhat 2-lobed. 



* Kosmos, ix. 2S2. No mention is made of this Order in the more recent paper by this 

 author on Verbreitung der Pflanzen durch die Excremente der Thiere.— Berlin, iSJg. 

 t See Parry: Proc. Davenport Acad. I. c. 

 X Annals of Botany, i. j. 



