OXALIDACEAE. 69 



of 2-5 partially united carpels, the styles wholly or partially distinct. 

 Fruit capsular. 



1. CATHABTOLINUM Beichenb. Herbs. Leaves alternate or occasionally 

 opposite, sometimes with stipular glands. Sepals 5, the inner ones at least with 

 gland-tipped teeth. Petals yellow, sometimes pubescent within near the base. 

 Androecium of 5 stamens, generally without staminodia. Styles 5, distinct or 

 united. Capsule 5-celled, or completely or incompletely 10-celled by false parti- 

 tions. FLAX. 



1. C. arenicola Small. Stems 2-7 dm. tall, corymbose above: leaves alternate, 

 erect or ascending; blades subulate or subulate-acicular, mostly less than 1 

 cm. long: outer sepals broadly oblong to oblong-ovate, 2.5-3 mm. long: cap- 

 sules spheroidal, about 2 mm. broad. Pinelands, L. keys. [E. K.] YELLOW- 

 FLAX. 



FAMILY 2. OXALIDACEAE. WOOD-SORREL FAMILY. 



Herbs or rarely shrubs, the sap sour. Leaves mostly alternate : blades 

 3-several-foliolate or 1-foliolate, the leaflets commonly notched at the apex. 

 Flowers perfect, essentially regular, cymose. Calyx of 5 persistent sepals. 

 Corolla of 5 white or colored petals. Androecium of 10-15 unequal 

 stamens: filaments partially united. Gynoecium of 5 partially united 

 carpels: styles distinct. Fruit a loculicidal capsule, or rarely baccate. 



1. XANTHOXALIS Small. Herbs. Leaf -blades palmately 3-foliolate: 

 leaflets notched at the apex. Flowers in umbel-like or dichotomous cymes. 

 Sepals 5, not tubercle-bearing. Petals broadened upward. Filaments usually 

 unappendaged. Capsule elongate, erect. 



1. X. corniculata (L.) Small. Stem and branches 5-40 cm. long, with spread- 

 ing hairs : leaflets deep-green ; blades 5-12 mm. broad, or larger, ciliate : sepals 

 3-4 mm. long: petals 7-10 mm. long. Hammocks and pinelands, L. keys. 

 [E. K.] (Ber., Bah., Cuba, Ant.) SOUR-GRASS. YELLOW WOOD-SORREL. 



FAMILY 3. ZYGOPHYLLACEAE. CALTROP FAMILY. 



Shrubs, trees or perennial herbs. Leaves opposite or alternate by the 

 suppression of one of each pair: blades compound. Flowers perfect. 

 Calyx of 4-6, mostly 5, sepals. Corlla of 4-6, mostly 5, petals, or rarely 

 wanting. Androecium of twice as many stamens as there are sepals. 

 Gynoecium of 2-4-united carpels. Fruit capsular, sometimes baccate at 

 maturity, sometimes separating into nut-like carpels. 



Herbs : corolla yellow or red. 



Nutlets 5, each with 3-5 one-seeded compartments : fruits spiny. 



1. TRIBULUS. 



Nutlets 8-10, each 1-seeded : fruits tuberculate. 2. KALLSTROEMIA. 



Shrubs or trees : corolla blue or purple. 3. GUAIACUM. 



1. TRIBULUS L. Diffuse herbs. Leaves pubescent. Sepals 5, decid- 

 uous. Petals white or yellow. Filaments unappendaged. Fruit spiny. 



1. T. cistoides L. Branches diffusely procumbent, pubescent: leaves 2-6 cm. 

 long; leaflets 12-16, the blades oblong or elliptic: sepals lanceolate, 8-11 mm. 

 long, acuminate: petals broad, 2-2.5 cm. long, bright-yellow: stamens shorter 

 than the petals: mature carpels 8-9 mm. long. Hammocks and waste places, 

 U. keys, L. keys, L. S. keys. Nat. of Trop. Am. (Bah., Cuba, Ant.) 

 BUR-NUT. CALTROP. 



