Part 3, 1911] 



BURSERACEAE 



Inflorescence elongate ; pedicels slender. 



Leaflets pubescent on both surfaces, usually 7 or fewer. 

 Leaflets nearly glabrous, generally ciliate, usually more 

 than 7. 

 Inflorescence compact ; pedicels short. 



Teeth of leaflets prominent, closely set ; fruit wrinkled. 

 Teeth of leaflets few, if any ; fruit not wrinkled. 

 Leaflets at most acute. 

 Leaflets acuminate. 

 Leaflets 3-7. 

 Leaflets more than 7. 



Leaflets lanceolate, usually 6 or 7 pairs. 

 Leaflets linear-lanceolate, more than 7 pairs. 

 Leaflets not glabrous throughout. 



Adult leaflets glabrous above, but more or less pubescent beneath ; 

 rachis pubescent. 

 Leaflets elongate, linear to linear-lanceolate. 

 Leaflets short-ovate to oblong. 

 Leaflets 3. 



Leaflets more than 3. 

 Leaflets 11-15. 



Fruit in panicles. 

 Fruit solitary. 

 Leaflets 5-9. 



Leaflets acuminate. 

 Leaflets at most acute. 



Inflorescence pubescent ; leaflets acute at base. 

 Leaflets twice as long as broad. 

 Leaflets only a little longer than broad. 

 Leaflets serrate. 

 Leaflets crenate. 

 Inflorescence probably always glabrous. 

 Adult leaflets pubescent on both sides. 

 Leaflets not coriaceous. 



Leaflets entire or subentire. 

 Leaflets more or less toothed. 

 Flowers subsessile. 

 Leaflets 15-21. 



Leaflets 3 cm. long; fruit 8 mm. in diameter. 

 Leaflets 5-7. 5 cm. long ; fruit 7 mm. in diameter. 64. 

 Leaflets 7-9. 65 



Flowers pedicelled. 



Fruit pubescent. 66 



Fruit glabrous. 



Rachis of the leaf toothed. 67 



Rachis of the leaf not toothed. 

 Branches dark-red or blackish. 



Margin of leaflets slightly revolute. 

 Margin of leaflets not revolute. 

 Branches light-reddish or gray. 



Branches reddish ; base of stone light. 

 Branches grayish ; base of stone dark. 

 Leaflets coriaceous and strongly rugose, especially beneath 

 Leaflets not rugose above. 

 Leaflets strongly rugose above. 



Pubescence on under surface of the leaflets rather scanty. 

 Rachis of the leaf more or less toothed ; inflorescence 



compact. 73. 



Rachis of the leaf entire ; inflorescence less com- _ 

 pact than in the last. 

 Pubescence on under surface of 

 and more or less matted. 

 Leaflets 11-21. 

 Leaflets 5-9. 



Rachis of the leaf toothed 

 Rachis of the leaf entire. 



E. penicilla tutu. 



58. E. Delpechianui, 



E. laxiftorum. 

 E. filicifolium. 

 E. longipedunculatum . 



62. E. pannosum. 



63. 



68. 



the leaflets abundant 



E. asplenifolium. 

 E. sessiliftorum. 

 E. queretarense. 



E. submoniliforme . 



E. Palmeri. 



E. Aloexylon. 

 E. rhoifolium. 



E. Macdougalii. 

 E. Goldmani. 



72. E. Schiedeanum. 



E. glabrescens. 

 E.jorullense. 



E. lanuginosum. 



E. excehnm. 

 E. cuneaium. 



1. Elaphrium epinnatum Rose, sp. now 



A tree 5-8 meters high ; second-year branches dark-brown, glabrous ; first-year branches 

 not seen ; leaves clustered at the ends of branches, simple, 2-4 cm. long, obtuse, broad 

 at base, crenate, slightly pubescent on both surfaces; petioles 1-2 cm. long; inflorescence 

 usually longer than the leaves, drooping, apparently few-flowered, in fruiting specimens 

 bearing only 1-3 drupes; fruiting pedicels slender, 7-10 mm. long; drupes globose, broad at 

 apex, 6 mm. long, glabrous. 



Type collected at Cape San Lucas, Lower California, December 30, 1905, Nelson & Goldman 

 7379 (TT. S. Nat. Herb. no. 565456). 



