GERANIACE^E. (GERANIUM FAMILY.) 43 



fanning an exterior cup-shaped calycalus : petals sulphur-yellow : styles united 

 almost to the top: capsule shorter than the sepals. — From S. Colorado to the 

 Missouri River. 



3. L. Kingii, Watson. Stems panicled above, shrubby at base: leaves 

 linear or narrowly oblong, obtuse : styles distinct : capsule somewhat exceeding 

 the sepals. — Bot. King's Exp. 49. Mountains of Utah. 



Order 17. ZYGOPHYL.L.4CEJE. 



Distinguished from allied orders by the opposite compound leaves, 

 with interposed stipules and entire dotless leaflets. — Sepals 5, distinct. 

 Petals hypogynous, imbricated in the bud. Stamens (in ours) twice as 

 many as the petals and inserted with them. Ovary 5 to 12-celled, with 

 a single terminal style. Fruit dry. — Ours are herbs or shrubs, with 

 solitary flowers on lateral or terminal naked peduncles, and ovary sur- 

 rounded at the base by a disk. 



1. Tribulus. Leaves abruptly pinnate, 6 to 10-foliolate. Fruit tuberculate. Herbs. 



2. Litrrea. Leaves 2-foliolate. Fruit densely hairy. Heavy-scented shrubs. 



1. TRIBULUS, L. 



Sepals mostly persistent. Petals fugacious. Disk annular, 10-lobed. 

 Stamens 10, the alternate filaments a little shorter and with a gland at base 

 on the outer side. Ovary 5 to 12-celled. Fruit lobed, separating into roughly 

 tuberculate carpels. — Loosely branched and hairy prostrate herbs, with ap- 

 parently axillary white or yellow flowers. 



1. T. maxim US, L. Leaflets ovate-oblong, more or less oblique: sepals 

 very hairy, linear, acuminate : fruit beaked by » stout style. — Kallstrosmia 

 maxima, Torr. & Gray. Fremont County, Colorado (Brandegee), to S. Cali- 

 fornia and Texas. 



2. LABBEA, Cav. Creosote-bush. 



Sepals deciduous. Petals unguiculate. Disk 10-lobed. Filaments winged 

 below with a bifid scale on the inner side. Ovary 5-celled. Fruit globose, 

 shortly stipitate, separating into 5 hairy one-seeded carpels. — Evergreen 

 heavy-scented shrubs, with nodose branches, and yellow flowers. 



1. L. Mexicana, Moric. Diffusely branched, 4 to 10 feet high, densely 

 leafy, of a yellowish hue : leaves nearly sessile ; the thick resinous leaflets 

 inequilateral, with a broad attachment to the rachis : sepals silky : scales 

 a little shorter than the filament, somewhat lacerate : fruit beaked by a 

 slender style. — S. Colorado to California and Texas. 



Order 18. GERANIACE^E. (Geranium Family.) 



Leaves generally with stipules, either lobed or compound. Flowers 

 on axillary peduncles, regular (in ours) and the parts in fives. Stamens 

 mostly 10, often somewhat monadelphous. Ovary 5-celled, with a cen- 

 tral axis. 



