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-pubescenb; capsule 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. Plam — Suhmont. Ap-N. 



2. X. Bushii Small. Stem slender, erect, 1-2 dm. high, villous; 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. LINAGE AE. 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. LiNUM. 



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. usitalissimum. 



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 — Suhmont. My-S. 



