POLYGALACEAE (M1LKWORT FAMILY) 307 



to obovate, somewhat cuneate at base and either obtuse or acute at apex, 

 3-7 cm. long, crenulate or crenate-serrate or almost entire: filaments villous 

 near the base: samara, including the broad wing, 12-18 mm. broad, either 

 truncate or emarginate at both ends. P. trifoliata. (P. angustifolia Benth., 

 a Mexican species, has been reported from our range, but such specimens may 

 prove to be P. crenidata.) Colorado to New Mexico and west to California. 



2. THAMNOSMA Torr. 



Low glandular desert shrubs. Strongly scented leaves simple and linear. 

 Alternate flowers purple or yellow, solitary. Sepals 4. Petals 4, erect. Sta- 

 mens 8, at the base of a cup-shaped crenate or lobed disk. Ovary stipitate, 

 2-lobed and 2-celled, with 5 or 6 ovules in each cell; style elongated. Cap- 

 sule didymous, coriaceous, dehiscent down the inner edge of each lobe. Seeds 

 4-6 in each cell, reniform. 



1. Thamnosma texanum Torr. Bot. Mex. Bound. Surv. 42. 1858. Woody 

 only at base, the slender stems 1-4 dm. high: flowers on short naked pedicels: 

 petals yellow tinged with purple. Southwestern Colorado and southward. 



63. POLYGALACEAE Reichenb. MILKWORT FAMILY 



Herbs with simple entire leaves and no stipules, remarkable for the seem- 

 ingly papilionaceous flowers, monadelphous stamens coherent with the petals, 

 and 1-celled anthers opening at the top. 



1. POLYGALA L. MILKWORT 



Herbaceous or somewhat shrubby, with racemose or spicate flowers. Se- 

 pals 5, very unequal, the 2 lateral large and petal-like. Petals 3, united to 

 each other and to the stamen-tube, the middle one hooded above and often 

 crested or beaked. Stamens 6 or 8. Ovary 2-celled; style long, curved, di- 

 lated above. Capsule membranaceous, flattened at right angles to the narrow 

 partition, often notched above. Seed carunculate at the hilum. 



Shrubby and spinescent. 



Subcinereous-pubescent 1. P. acanthocarpa. 



Glabrous . . . . . . . . . . . 2. P. subspinosa. 



Herbaceous or nearly so; spines wanting. 



Annual; leaves verticillate 3. P. verticillata. 



Perennial; leaves alternate . . . ...*.$ . . 4. P. alba. 



1. Polygala acanthocarpa Gray, Proc. Am. Acad. 11: 73. 1876. Some- 

 what shrubby, 4-7 dm. high, subcinereous-pubescent, armed with slender 

 spines: leaves linear-spatulate : flowers subaxillary, scattered, white; pedicels 

 bibracteolate at base: keel short, boat-shaped, with a boss on the back. 

 Probably coming into our range at the southwest. 



2. Polygala subspinosa Wats. Am. Nat. 7: 299. 1873. Perennial, her- 

 baceous, glabrous or more or less pubescent; stems 5-20 cm. high, branched 

 above, the branches often spinose: leaves scattered, 1-3 cm. long, oblong or 

 oblanceolate, acute or obtuse, attenuate to the base: raceme loose, few- 

 flowered; bracts small and scarious; j>edicels becoming reflexed, shorter than 

 the flowers: sepals naked or ciliate, the wings oblong, 8-10 mm. long and 

 equaling the petals; keel hooded, crested with a broad saccate process: style 

 linear; capsule orbicular, emarginate, short-stipitate. From Colorado to 

 the Pacific southwest. 



3. Polygala vertjcillata L. Sp. PI. 706. 1753. Slender, 2-3 dm. high: stem 

 leaves whorled in fours, sometimes in fives; those of the branches scattered, 

 linear: spikes peduncled, dense, slender; the bracts falling with the flowers, 

 which are small, greenish-white or barely tinged with purple, the crest of the 



