14 ZYGOPHYLLACEAE 



11. Linum spergulinum A. Gray. Slender Dwarf Flax. Fig. 2998. 



Linum spergulinum A. Gray, Proc. Atner. Acad. 7: 333. 1868. 

 Hesperolinon spergulinum Small, N. Amer. Fl. 25: 86. 1907. 



Stems slender, 1.5^ dm. high, dichotomously branching above, the ultimate branches filiform, 

 pubescent above the forks. Leaves linear, 1-2 cm. long, entire, somewhat involute ; bracts similar 

 but smaller; pedicels filiform, often 10-15 mm. long, straight or the tips curved upward; sepals 

 narrowly ovate-lanceolate, at least the inner glandular-ciliate ; petals white tinged with rose- 

 pink, 5-7 mm. long, distinctly 2-lobed at base, the lobes somewhat thickened and rounded; 

 capsules about 2.5 mm. long, exceeding the sepals. 



Dry rocky ridges and grassy slopes, Upper Sonoran Zone; California Coast Ranges, from Mendocino County 

 to Napa and Santa Clara Counties. Type locality: Cloverdale, Sonoma County. June-July. 



12. Linum californicum Benth. California Dwarf Flax. Fig. 2999. 



Linum californicum Benth. PI. Hartw. 299. 1848. 

 Hesperolinon californicum Small, N. Amer. Fl. 25: 86. 1907. 



Stems 1-4 dm. high, glabrous and glaucous, dichotomously branched, the branches mostly 

 ascending. Leaves narrowly linear, 1-3 cm. long, involute, entire ; pedicels short and the flowers 

 usually in few-flowered cymules terminating the branches ; pedicels mostly less than 5 mm. long ; 

 sepals lanceolate-acuminate, becoming 4-5 mm. long ; irregularly glandular-ciliate ; petals tinged 

 with pink, 4-6 mm. long; capsule broadly ovoid, 3 mm. long. 



Open gravelly soils. Upper Sonoran Zone; foothills of the Sierra Nevada and the Inner Coast Ranges sur- 

 rounding the Sacramento Valley, California. Type locality: probably in the foothills of Butte County. April- 

 June. 



13. Linum congestum A. Gray. Marin Dwarf Flax. Fig. 3000. 



Linum congestum A. Gray, Proc. Amer. Acad. 6: 521. 1865. 



Hesperolinon congestum Small, N. Amer. Fl. 25: 86. 1907. 



Linum californicum var. congestum Jepson, Man. Fl. PI. Calif. 587. 1925. 



Stems 1-3 dm. high, glaucous and more or less pubescent, especially immediately above the 



forks ; branches dichotomous, ascending, in the typical form rather short and forming a congested 



inflorescence ; pedicels short ; sepals lanceolate, 3 mm. long, pubescent on the back and at least 



the inner glandular-ciliate on the margins ; petals white, tinged with pink, 5-6 mm. long ; capsule 



ovoid. 



Rocky and gravelly soils, Upper Sonoran Zone; San Francisco Bay region, California. Type locality: 

 Marin County. April-June. 



Linum congestum var. confertum A. Gray ex Trelease, Trans. St. Louis Acad. 5: 19. 1887. Differs from 

 the typical species in having more elongated and open branching, with the flowers in few-flowered glomerules 

 at the ends of the branches. About the same range as the species, but apparently more common. Type locality: 

 Mare Island, Solano County, California. 



Family 74. ZYGOPHYLLACEAE. 

 Caltrop Family. 



Herbs, shrubs or some tropical species trees, often strong-scented, the branches 

 usually articulate at the nodes. Leaves generally opposite, pinnate or digitately 

 2-3-foliolate, the leaflets entire. Stipules persistent. Flowers perfect, regular or 

 nearly so, borne on axillary peduncles. Sepals usually 5, distinct or united at the 

 base. Petals as many as the sepals or sometimes absent. Stamens as many as the 

 petals or 2 or 3 times as many, the alternate ones sometimes longer ; filaments often 

 with a scale near the middle. Ovary 4-12-celled; ovules 1 to many in each cell; 

 style terminal, with usually a simple stigma. Fruit an angled capsule or splitting 

 into several smooth or spinescent nutlets, or in some species drupaceous. Seeds with 

 or without endosperm; embryo straight or curved. 



A family of about 20 genera and 150 species widely distributed in warm temperate and tropical regions. 



Flowers purple; stipules spiny; leaflets palmately 1-7-foliolate. 1. Fagonia. 



Flowers yellow; stipules not spiny; leaves pinnate. 



Shrub; fruit densely villous. 2. Larrea. 



Herbs; fruit spiny or tubercled. 



Fruit spiny, splitting into five 3-S-seeded nutlets. 3. Tribulus. 



Fruit not spiny, often tubercled, splitting into ten to twelve 1-seeded nutlets. 4. Kallstroemia. 



1. FAGONIA [Tourn.] L. Sp. PI. 386. 1753. 



Diffusely branched plants with a woody base, the stems angled and channeled, glabrous 

 or glutinous. Leaves opposite, 1-7-folioIate, palmately divided, the leaflets entire, more or 

 less spinose-tipped. Stipules subulate, spinulose-tipped. Flowers solitary, purple. Sepals 

 5, imbricate, caducous. Petals 5, clawed, caducous. Stamens 10, inserted on an incon- 



