534 OXALIDACEAE 



Stamens 10; filaments united into a tube at the base. Ovary elongate; styles 

 filiform or subulate. Capsule columnar or oblong, prismatic, erect. 



Stem appressed-pubescent; cap.sTile pubescent. 1. X. stricta. 



Stem loosely pubescent, or nearly glabrous; capsule glabrous. 2. X. Bushii. 



1. X. stricta (L.) Small. Stems erect or decumbent in age, 0.5-5 dm. long, 

 strigillose; leaflets 15-20 mm. wide; peduncles longer than the petioles; sepals 

 4—5 mm. long; petals pale yellow, 5-10 mm. long; capsule columnar, 16-30 mm. 

 long, rather abruptly pointed. Oxalis stricta L. Woods, roadsides, and culti- 

 vated grounds: N.S. — Fla. — N.M. — Wyo.; Mex. Plain — Submont. Ap-N. 



2. X. Bushii Small. Stem slender, erect, 1-2 dm. high, "^nllous; leaflets 

 broadly obcordate, glabrous, 8-20 mm. long; peduncles very slender, about 5 

 cm. long; inflorescence cymose, but often reduced to 2-3 flowers and umbel-like; 

 sepals 4-5 mm. long, oblong; petals 6-7 mm. long; capsule columnar, 12-15 mm. 

 long. Oxalis Bushii Small. Oxalis and Xanthoxalis coloradensis Rydb. River 

 bottoms: N.S.— Ga. — Colo.— S.D. Plain— Mont. My-Au. 



Family 68. LINACEAE. Flax Family. 



Herbs with alternate leaves, with or without stipules. Flowers perfect, 

 regular, racemose or paniculate. Sepals and petals 5, rarely 4 or 6. Sta- 

 mens as many as the sepals, monadelphous. Gynoecium of 5, sometimes 2 

 or 3, united carpels. Fruit a capsule, opening by twice as many valves as 

 there are carpels. 



stigmas introrse and more or less elongate; sepals glandless; flowers in ours blue, rarely 

 white. 1. LiNXTM. 



Stigmas terminal and capitate; sepals, at least the inner ones, with marginal glands; 

 flowers in ours yellow. 2. Cathartolinum. 



1. , LINUM L. Flax, Blue Flax. 



Annual or perennial glabrous plants, sometimes woody at the base. Leaves 

 alternate, without stipules or stipular glands, narrow, entire. Sepals 5, per- 

 sistent. Petals 5, in ours blue, or rarely white, unappendaged and entire at the 

 base. Stamens 5; filaments dilated and united at the base, each sinus with a 

 short staminodium. Gynoecium 5-carpellary, not cartilaginous at the base; 

 styles 5, elongate, distinct or united; stigmas elongate, introrse. Capsules 5- 

 celled, the carpels with incomplete false partitions. Seeds flat, elongate- 

 lenticular. 



Inner sepals ciliate; stigmas much elongate; introduced annual. 1. L. usilatissimum. 



Sepals not ciliate; stigmas rather short; native perennials. 



Sepals over 5 mm. long at maturity, more than one-half as long as the capsule. 



2. L. Lewisii. 

 Sepals less than 5 mm. long, less than one-half as long as the capsule. 



3. L. pratense. 



1. L. usitatissimum L. Stem 2-8 dm. high, glabrous; leaves narrowly 

 linear-lanceolate, 3-nerved, sessile; sepals acuminate, the outer elliptic or elliptic- 

 lanceolate, the inner elliptic-ovate or ovate, ciliate, 7-9 mm. long, all 3-nerved 

 at the base; petals blue 1-1.5 cm. long; capsule 6-8 mm. long. Waste places 

 and old fields; occasionally escaped from cultivation, native of Eu. My-S. 



2. L. Lewisii Pursh. Stem 2-7 dm. high, often branched at the base, ob- 

 scurely striate; leaves erect, linear or nearly so, 1-2 cm. long; sepals 5.5-7 mm. 

 long, the outer ovate, short-acuminate, the inner broader, mucronate; petals 

 blue or rarely white, 1.5-2 cm. long. Plains and hills: Man. — Neb. — Tex. — 

 Calif. — Alaska; n Mex. Plain — Mont. My-Au. 



3. L. pratense (Norton) Small. Stem 1-6 dm. high, striate in age, commonly 

 branched at the base; leaves commonly numerous and crowded towards the base, 

 narrowly linear or subulate, 0.5-1 cm. long, rather succulent; bracts subulate; 

 sepals mostly 4-5 mm. long, ovate to oblong-ovate, the outer acute or short- 

 acuminate, the inner broader, mucronulate; petals blue, 1-1.5 cm. long. Dry 

 plains: Sask. — Tex. — Ariz. — Nev. — Wyo. Plain — Submont, My-S. 



