110 NORTH AMERICAN FLORA [Volume 25 



of the alternate smaller leaves, 3-4 cm. long ; sepals lanceolate, acuminate, half as long as 

 the petals, silky-pubescent, caducous; petals yellow, about 2 cm. long, 1-2 cm. broad; 

 ovary hirsute ; carpels 3-5-seeded, tuberculate, each with 2 large stout divergent spines 

 and scattered smaller ones. 



Type locality : Tropical America. 



Distribution : Georgia, Florida, Texas, West Indies, Mexico, and Central and South America. 



Illustrations : Jacq. Hort. Schonb. pi. 103 ; A. Gray, Gen. 111. 2 : pi. 145 ; Bot. Reg. 10 : pi. 

 791 ; Diet. Sci. Nat. pi. 123 ; Pluk. Aim. pi. 67, f. 4; Descourt. Fl. Ant. 4: pi. 250 (?) (as Tribulus 

 maxim us). 



2. Tribulus alacranensis Millsp. Field Columb. Mus. Publ. 

 Bot. 2 : 54. 1900. 

 Perennial runner from a long ligneous rootstock ; stems many, ligneous, 5-25 dm. 

 long, thick, 4-7 mm. in diameter, many-striate ; joints all about 1.5 cm. long; nodes rough 

 with the withered persistent bracts and stipules of deciduous petioles ; branchlets infre- 

 quent along the branches, mainly aggregated at the ends, appressed silvery-hirsute or 

 tomentulose ; stipules linear or subulate, acute, commonly the length of the petiole ; petioles 

 5-10 mm. long; leaves 2-5 cm. long, densely silvery -hirsute or tomentose ; leaflets 4-8 

 pairs, obliquely oblong or elliptic-oblong, 10-15 mm. long, 4-5 mm. wide, apiculate ; 

 flowers terminal, closing early in the sun ; petals bright-yellow, 1-1.5 cm. long; anthers 

 2.5-3 mm. long, oblong ; ovary clothed with long straight hyaline setae that persist on the 

 mature fruit; fruit 7-8 mm. long; carpels truncate, somewhat tuberculate, 4-6-spiued, the 

 main pair divergent, the apical pair short. 



Type locality : Pajaros Island, Alacran Shoal, Gulf of Mexico. 

 Distribution: Allison, Pajaros, and Perez Islands, off Yucatan. 



3. Tribulus terrestris L,. Sp. PI. 387. 1753. 

 A diffuse trailing annual herb ; stems hirsute and slightly swollen at the nodes ; stipules 

 subulate, caducous; petioles about as long as the leaflets ; leaves 2-5 cm. long; leaflets 

 about 5-7 pairs, somewhat oblique, oblong or elliptic, 3-13 mm. long, acutish or obtuse, 

 silky-strigose beneath, the terminal pair smaller ; peduncles usually in the axils of the 

 alternate smaller leaves and shorter than the leaves ; sepals caducous ; petals obovate, about 

 4 mm. long, light -yellow ; carpels bony, 5, by abortion 3-celled, each with 2 divergent 

 stout spines and 2 or more smaller ones and also somewhat tuberculate, sparingly hispid 

 and sometimes puberulent. 



Type locality : Southern Europe. 



Distribution : South Carolina and Illinois, Nebraska, Arizona, southward to Mexico and 

 Brazil, introduced ; ballast grounds, Hunter's Point, Long Island, N. Y., and Philadelphia, Pa.; 

 native of the Mediterranean region and western Asia. 



Illustrations: Sibth. Fl. Graeca/>/. 372; Britt. & Brown, 111. Fl./. 2267; Lob. Ic. 2 : pi. 84; 

 Barr. PI. pi. 55S ; Lam. Tab. Encyc. pi. 346, f. 1 ; Reichenb. Fl. Germ. 5 : 161 ; Sehkuhr, Handb. 

 pi. 115. 



6. KALLSTROEMIA Scop. Introd. 212. 1777. 



Diffuse and branching herbs. Stems procumbent, hirsute, sometimes ligneous. 

 Leaves abruptly pinnate, opposite, one of each pair alternately smaller than the other or 

 lacking; leaflets oblique. Stipules subulate. Flowers solitary, orange, yellow, or whitish. 

 Peduncles axillary, swollen below the calyx. Sepals 5 or 6, lanceolate to linear-subulate, 

 mostly persisting, marcescent, usually much shriveled or contracted on the fruiting calyx. 

 Petals 4-6, obovate or obcordate, spreading, longer than the sepals, caducous. Stamens 10 

 or 12, hypogynous. Filaments filiform, those opposite the petals exterior and aduate to the 

 petals, the alternate ones smaller and subtended by a small gland externally. Ovary sessile, 

 8-12-celled, without transverse septa. Styles united, columnar, or subulate from a conic 

 base. Stigma capitate. Fruit vertically 8-12-angled, muricate, roughened or tuberculate, 

 separating at maturity into 8-12 bony, indehiscent, 1- rarely 2-seeded, dorsally tuberculate 

 nutlets, leaving a more or less persistent thick styliferous central axis. Seeds obovate. 

 Testa membranaceous. 



Type species, Tribulus maximus L. 



