664 OXALIDACEAE 



22 Linum Berlandferi Hook. Annual or perhaps perennial, nearly glabrous. 

 Stems simple, 1-2.5 dm tall, or branched at the base, the branches erect or ascending, 

 corymbose : leaves clear green ; blades lanceolate or linear, 1-2.5 cm. long, spreading or 

 ascending, acuminate, the lateral nerves marginal : pedicels stout, angled, longer than the 

 calyx : outer sepals lanceolate, 8-11 mm. long, acuminate, copiously glandular-serrate ; 

 inner sepals nearly like the outer but with slightly finer teeth : corolla yellow, 4-4.5 cm. 

 broad : capsules globose-ovoid, 4-4.5 mm. long, obtuse, much shorter than the sepals. 



On plains and praries, Texas. Spring and summer. 



13. Linum sanctum Small. Annual or perennial, deep green. Stems 1.5-3 dm. 

 tall, coryrabosely branched above : leaves approximate ; blades narrowly oblong to linear- 

 oblong, 1.5-3.5 cm. long, ascending, the lateral nerves not marginal : pedicels shorter 

 than the calyx : outer sepals lanceolate, 10-12 mm. long, acuminate, rather sparingly gland- 

 ular toothed ; inner sepals much shorter than the outer but with many approximate finer 

 teeth : corolla yellow, about 3 cm. broad : capsule not seen. 



On plains or prairies, southern Texas. Summer. 



14. Linum multicaule Hook. Annual or perhaps perennial, puberulent. Stems 

 more or less densely tufted, 1-3 dm. tall, simple or corymbosely branched above : leaves 

 numerous, firm, appressed or erect, commonly imbricated ; blades linear or linear-subulate, 

 3-8 mm. long, acute, finely ciliate : pedicels stout, mostly longer than the sepals : outer 

 sepals 4.5-5 mm. long, each with an elliptic to oval ciliate body and a subulate terminal 

 awn ; inner sepals similar but slightly smaller : corolla yellow, 1.5 cm. broad : capsules sub- 

 globose, 4 mm. long, shorter than the sepals. 



On plains and prairies, Texas. Spring and summer. 



FAMILY 4. OXALIDACEAE Lindl. WOOD-SORREL FAMILY. 



Annual or perennial acaulescent or leafy-stemmed herbs, or rarely shrubs, 

 with rootstocks or scaly bulbs, and a sour sap. Leaves basal or cauline : petioles 

 with free or adnate stipules, or these obsolete : blades usually 3-foliolate, some- 

 times 1-foliolate, usually pinnate or digitate : leaflets commonly notched at the 

 apex. Flowers perfect, essentially regular, solitary or in axillary or terminal, 

 peduncled, umbel-like or dichotomous cymes. Calyx of 5 often unequal, imbri- 

 cated, persistent sepals. Corolla of 5 white, pink, rose, purple or yellow convo- 

 lute petals, usually broadened upward, entire or notched at the apex. Androe- 

 cium of 10-15 stamens, or twice or thrice as many as the sepals. Filaments 

 united below, in 2 sets of different lengths. Gynoecium of 5 united carpels. 

 Ovary 5-celled, 5-lobed. Styles 5, distinct. Stigmas capitate. Ovules 2-inany 

 in each cavity. Fruit a globose or columnar loculicidal capsule, or rarely berry- 

 like. Seeds with a dehiscent arilloid outer coat and a firm, often ridged, inner 

 coat. Embryo straight in fleshy endosperm. Cotyledons flat. 



Plants acaulescent, perennial, succulent : corolla not vellow. 



Rootstocks elongated, scaly near the ends : flowers homogenous. 1. OXALIS. 



Rootstocks abbreviated, bulb-like : flowers heterogonous. 2. IOXOXALIS. 



Plants caulescent, annual or perennial, not succulent : corolla yellow. 



Leaf-blades 1-foliolate : stipules free, bristle-like. 3. MONOXALIS. 



Leaf-blades 3-foliolate : stipules adnate, a dilation of the base of the petioles or 



obsolete. 

 Leaflets pinnate : ovary and capsule drooping, depressed at the apex : stigmas 



2-cleft. 4. LOTOXALIS. 



Leaflets palmate : ovary and capsule erect, narrowed at the apex : stigmas 



capitate. 5. XANTHOXALIS. 



1. OXALIS L. 



Perennial herbs, with slender more or less scaly rootstocks. Leaves basal, solitary or 

 several together : petioles dilated at the base ; blades palmately 3-foliolate ; leaflets notched 

 at the apex, usually with a membranous fold in the sinus. Scapes solitary or several to- 

 gether, topped by a single pedicel or rarely with an umbel-like cyme. Flowers perfect, 

 homogonous. Sepals 5, the inner longer than the outer. Petals white or pink, delicate, 

 much longer than the sepals, often obliquely notched at the apex. Stamens 10 : filaments 

 commonly glabrous. Capsule relatively short. Seeds few or several in each cavity, 

 pitted and grooved or striate. WOOD-SORREL. 



1. Oxalis Acetos61la L. Rootstocks slender, scaly at the ends. Foliage pubescent 

 with scattered brownish hairs : leaves 2-6 together : leaflets 3, the blades obcordate, 10-15 



