74 
SAXIFRAGACEAE. 
PHILADELPHUS. “Syringa”’. Mock Orange. 
(Family Saxifragaceae). 
Shrubs, mostly with exfoliating 
\ outer cortex: deciduous. Twigs 
far: more or less lined or obscurely 
AI hexagonal: pith moderate, round- 
| “4 ed, pale, continuous. Buds soli- 
Nyy al tary, sessile with 2 nearly valvate 
. mostly hairy scales, the end-bud 
lacking. Leaf-scars opposite or 
exceptionally in whorls of 3, half- 
round with a thin membrane more 
or less covering the bud, or cres- 
cent-shaped when this is burst, 
connected transversely: bundle- 
traces 3: stipule-scars lacking. 
References under Decumaria. 
1. Outer cortex persistent, becom- 
ing gray. 2. 
Outer cortex straw-colored or 
red, quickly exfoliating. 3. 
2. Membrane tough. 
(1). P. pubescens. 
Membrane thin. (2). P. Lewisii. 
. Leaf-sear scarcely reaching the end of bud. 4. 
Leaf-sear broad, covering the bud until burst. 7. 
. Leaf-scar narrow: twigs slender. 5. 
Leaf-sear broad: twigs moderate. P. ealifornicus. 
. Twigs glabrous. (3). P. microphyllus. 
Twigs more or less villous or canescent. 6. 
. Pubescence scanty: buds half-covered. < P. Lemoinei. 
Pubescence abundant: buds fully exposed. 
(4). P. hirsutus. 
. Twigs more or less villous: fruit racemed. P. coronarius. 
Twigs glabrous: fruit nearly solitary. (5). P. inodorus. 
