520 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



1. POLYGALA 



Herbs or undershrubs ; flowers mostly in narrow terminal racemes, 

 sometimes few or solitary in the leaf axils; petals united below, form- 

 ing a dorsally -cleft tube, the lower petal (keel) attached at base to 

 the stamen tube; capsules dehiscent; seeds with a caruncle, this 

 usually umbrellalike or veillike, with a thickened center (umbo), and a 

 scarious marginal portion. 



These dainty plants are interesting because of the unusual structure 

 of their flowers and seeds. Most of the species are reported to be 

 distasteful to grazing animals, but the somewhat woody P. macra- 

 denia is browsed occasionally. 



Key to the species 



1. Keel petal not crested or beaked, at most apiculate; flowers not more than 



6 mm. long: P. acanthoclada, an intricately branched shrub with scattered 



yellowish flowers, these solitary or in fascicles of not more than 4, might be 



sought here (2) . 



2. Leaves conspicuously dotted with large sessile glands, not dimorphic, very 



numerous, less than 10 mm. long, linear to oblong-lanceolate; flowers 



axillary, mostly solitary; plant suffrutescent, densely short-pilose; 



stems numerous, seldom more than 20 cm. long; wing petals purple, 



pubescent, the keel petal greenish yellow 1. P. macradenia. 



2. Leaves not gland-dotted, more or less dimorphic, the lower ones broader and 



shorter than the upper ones; flowers few or somewhat numerous in loose 



terminal racemes; capsules ciliolate; plants herbaceous, of very similar 



appearance (3). 



3. Caruncle of the seed with the depth of the entire or denticulate scarious 



marginal portion less than the height of the umbo (4). 



4. Capsules remaining more or less pubescent on the sides; middle and 



upper leaves linear-lanceolate or linear-elliptic, 2 to 3 mm. wide, the 



lower leaves oblanceolate 2. P. piliophora. 



4. Capsules glabrous on the sides when mature; middle and upper leaves 

 linear or lance-linear (5) . 

 5. Middle and upper leaves scalelike, 5 to 10 mm. long, 1 to 1.5 mm. 



Wide 3. P. BARBEYANA. 



5. Middle and upper leaves not scalelike, 15 to 30 mm. long, 1.5 to 3 mm. 

 wide; wing petals greenish, tinged with purple_4. P. racemosa. 

 3. Caruncle of the seed with the depth of the lobed or lobulate scarious 

 marginal portion equaling or exceeding the height of the umbo; wing 

 petals greenish purple or violet (6) . 

 6. Capsules glabrous on the sides at maturity; caruncle not veillike, cover- 

 ing only the tip of the seed, the scarious portion not much deeper 

 than the height of the umbo (7). 

 7. Upper leaves less than 25 mm. long, the lowest leaves less than 10 mm. 

 long; stems less than 20 cm. long; capsules oblong-oval. 



5. P. reducta. 



7. Upper leaves mostly 20 to 35 mm. long, the lowest leaves seldom less 



than 10 mm. long; stems commonly at least 20 (up to 45) cm. long; 

 capsules broadly oval, ovate, or slightly obovate. 



6. P. LONGA. 



6. Capsules pubescent on the sides at maturity (seldom glabrate) ; caruncle 

 veillike, covering one-fourth or more of the seed, the scarious 

 portion much deeper than the height of the umbo (8) . 



8. Hairs of the stem all incurved or subappressed; middle and upper 



leaves up to 12 mm. wide, but usually much narrower. 



7. P. OBSCTJRA. 



8. Hairs of the stem all wide-spreading; middle and upper leaves not 

 more than 6 mm. wide 8. P. orthotricha. 



