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RHAMNACEAE. 



MlCROBHAMNUS. 



(Family Rhamnaceae). 



Intricately branched shrubs of 

 the southwest: deciduous. Twigs 

 glabrous, terete, slender, with 

 short internodes, spine-tipped: 

 pith minute, roundish, continu- 

 ous. Buds solitary or collaterally 

 branched in spine formation, ses- 

 sile, minute, round, appressed, 

 quickly developing into short 

 foliage spurs on which numerous 

 stipular scales persist for a long 

 time. Leaf-scars alternate, more 

 or less raised, crescent-shaped, 

 minute: bundle-trace 1, indistinct: 

 stipules persistent, minute, trian- 

 gular. The very small leaves, 

 when present, are closely revolute 

 to the midrib as in Loiseleuria 

 and some other Ericaceae and in 

 some Empetraceae. 



Like the preceding genus, 



Microrhamnus often forms dense masses of chaparral. 



Twigs with light gray splitting epidermis. M. ericoides. 



