100 NYCTAGINACEAE 



succulent, green or slightly tinged with red-purple, glabrous or nearly so. Leaves rhombic-ovate 

 to lanceolate, obtuse, S-20 mm. long; petioles slender, equaling or longer than the blades, gla- 

 brous or pubescent; flowers polygamous, in dense, short and thick spikes, which are usually 

 subtended by a few capitate axillary clusters; bracts inconspicuous, usually much shorter than 

 the calyx ; sepals 2 or 3, oblong, acutish ; stamens 3 ; utricle exceeding the sepals, smooth, 3-5- 

 nerved, smooth, indehiscent ; seeds oval, 1 mm. long, dark reddish brown, shining. 



Ballast at Portland, Oregon, and along streets and railroads in central and southern California; also 

 adventive along the Atlantic Coast; Europe, Africa, and South America. May-Nov. 



2. TIDESTROMIA Standley, Journ. Wash. Acad. 6: 70. 1916. 



Annual or perennial herbs or suffruticose at base, canescent with branched hairs. 

 Leaves opposite, with broad rounded entire blades and slender petioles. Flowers glomerate 

 in the axils of the leaves, perfect, minute, subtended by a bract and 2 bractlets, these small, 

 pubescent and hyaline; calyx 5-parted, sepals united at base, equal. Stamens 5, the fila- 

 ments united below into a cup, with or without intervening staminodia; anthers 2-celled. 

 Ovary globose; style short; stigma simple or 2-lobed; ovule solitary, pendent. Utricle 

 slightly compressed, smooth and glabrous. [Name in honor of the contemporary Ameri- 

 can botanist, Ivar Tidestrom.] 



A genus of 3 species, native of the arid southwestern United States and adjacent Mexico. Type species, 

 Achyranthes lanuginosa Nutt. 



1. Tidestromia oblongifdlia (S. Wats.) Standley. Arizona Honey-sweet. 



Fig. 1567. 



Cladothrix oblongifolia S. Wats. Proc. Amer. Acad. 17: 376. 1882. 

 Cladothrix cryptantha S. Wats. Proc. Amer. Acad. 26: 125. 1891. 

 Tidestromia oblongifolia Standley. Journ. Wash. Acad. 6: 70. 1916. 



Perennial from a stout woody taproot, the whole plant densely canescent with much- 

 branched hairs ; stems widely branching, spreading, more or less suffruticose at the base, 2-6 dm. 

 long. Leaves broadly ovate to oblong, 1-4 cm. long, usually longer than the petioles ; the small 

 floral leaves united below, forming an involucre with an oblong-turbinate tube 2-3 mm. long 

 and 3 broadly ovate lobes 2-4 mm. long ; bractlets minute, much shorter than the calyx ; sepals 

 lanceolate, 1 mm. long; seeds 0.5 mm. long. 



Dry sandy soils, Lower Sonoran Zone; deserts of southern California to southern Nevada and Arizona. Type 

 locality: on the banks of the Colorado, near Chimney Peak, California. April-Dec. 



Achyranthes repens L. Sp. PI. 205. 1753. Prostrate perennial herb with villous foliage. Leaves rhombic- 

 ovate, 5-15 cm. long; flowers in short spikes, sessile in the axils; bracts ovate, ciliate; sepals unequal, 3-5 mm. 

 long, ovate, villous on the nerves. Sparingly adventive in southern California (Los Angeles, Oceanside), native 

 of Mexico. 



Family 38. NYCTAGINACEAE * 



Four-o'clock Family. 



Herbs with fragile stems and tumid joints, and entire petiolate exstipulate mostly 

 opposite leaves. Flowers perfect, with a calyx-like involucre or separate bracts. 

 Calyx corolla-like, campanulate or salver-shaped, 4-5-lobed or 4-5-toothed, con- 

 stricted above ovary. Petals wanting. Stamens hypogynous ; filaments filiform; 

 anthers 2-celled, dehiscent by lateral slits. Ovary superior, enclosed by the tube of 

 the persistent calyx, 1 -celled, 1-ovuled; style short or elongated; stigma capitate, 

 depressed-capitate or linear. Fruit an anthocarp often costate or winged, enclosing 

 the free achene. Embryo in ours curved, cotyledons enclosing the mealy or fleshy 

 endosperm. 



About 20 genera and 160 species, of warm temperate and tropical regions. 



Flowers borne on nerves of large foliaceous bracts. 1. Hermidtum. 



Flowers in calyx-like involucres or subtended by bracts shorter than the inflorescence. 



Anthocarp lenticular with the margins revolute and usually dentate. 5. Allionia. 



Anthocarp not lenticular. 



Bracts united into an involucre. 



Anthocarp definitely angled or ribbed; involucre accrescent. 6. O.xybaphus. 



Anthocarp smooth or nearly so; involucre but little changed in fruit. 7. Mirabilis. 



Bracts free. 



Stigma linear; perianth salverform. 8. Abronia. 



Stigma peltate or capitate; perianth not salverform. 

 Perianth funnelform, 3-10 cm. or more long. 



Perianth 3-4 cm. long; anthocarp conspicuously winged. 2. Selinocarpus. 



Perianth 10 or more cm. long, angled or sulcate. 3. Acleisanthes. 



Perianth campanulate or short-funnelform, 2-8 mm. long. 4. Boerhaavia. 



Text contributed by Roxana Stinchfield Ferris. 



