KEYS LEAVES ALTERNATE xxiii 



176. Only the stipules pungent. 177. 

 Pungent leaves also present. See 146. 

 Pungent twigs also present. See 181. 

 Prickles also present. See 186. 



177. Leaf-scars on a finally torn membrane. p. 157. Robinia. 

 Leaf-scars small, not on an articular membrane. 178. 



178. Bundle-trace one. 179. 



Bundle-traces 3: fruit a screw-like pod. p. 135. Prosopis. 



179. Slender branchlets from the nodes: fruit fleshy. 



p. 212. Zizyphus. 

 Without this combination of characters. 180. 



180. Leaf-scars low: fruit umbrella-shaped. p. 213. Paliurus. 

 Leaf -scars raised: fruit a legume. p. 133. Acacia. 



181. Wood appearing "endogenous": a supra-axillary 



spine present, p. 46. Bougainvillea. 

 Wood distinctly in a zone between pith and bark. 182. 



182. Pith chambered or excavated. p. 131. Prinsepia. 

 Pith spongy: spine by side of bud. p. 235. Lycium. 

 Pith continuous. 183. 



183. Aromatic: evergreen or with green twigs.. 184. 



Not aromatic: evergreen: leaves simple, p. 99. Pyracantha. 

 Neither aromatic nor evergreen nor green-twigged. 186. 



184. Deciduous: spines strong. p. 169. Poncirus. 

 Evergreen: leaves compound. 185. 



185. Leaflets 3: spines needle-like. p. 167. Triphasia. 

 Leaflet 1, but disarticulating from its stalk, p. 168. Citrus. 



186. Sap more or less milky. 187. 

 Sap not milky. 188. 



187. Without stipule-scars: bundle-traces 3. p. 302. Bumelia. 

 With stipule-scars: bundle-traces more. p. 35. Maclura. 



188. Leaf-scars on finally torn membranes. 189. 

 Without such articular membranes. 190. 



189. Spines branched, often clustered. p. 139. Gleditsia. 

 Spines unbranched. p. 143. Sophora. 



