AMARANTH FAMILY 255 



Pistillate inflorescence of slender interrupted spikes; fruit circumscissile. 1. A. tamarisdna 

 Pistillate inflorescence of closely clustered spikes; fruit indehiscent or irregularly splitting. 



2. A. altissima. 



1. A. tamariscina (Nutt.) Wood. Stem erect, much branched, 1-2 m. 

 long; leaf-blades lanceolate or ovate-lanceolate, obtuse or notched at the apex, 

 entire or undulate; bracts lanceolate, spinulose-tipped, scarious-margined! 

 Swamps and alluvial soil: 111. S.D. Colo. N.M. 'La. Plain. Jl-S. 



2. A. altissima Riddell. Stem 1-3 m. high, with flexupse branches; leaf- 

 blades lanceolate to rhombic-ovate, entire; bracts rigid, acuminate; sepals of the 

 staminate flowers lanceolate, acuminate. A. tuberculata Moq. Swamps' Ont 

 S.D. Colo. Ohio. Plain. Jl-S. 



3. TIDESTROMIA Standl. 



Annual or perennial herbs, with stellate pubescence and mostly opposite, 

 entire or merely undulate, short-pet ioled leaves. Flowers perfect, subtended by 

 3 bracts, solitary or clustered in the axils. Sepals 5, unequal, pubescent. Sta- 

 mens 5; filaments united at their bases; anthers 1-celhd. Ovary 1-celled; styles 

 short; stigmas capitate or 2-lobed. Ovules solitary. Utricle subglobose, inde- 

 hiscent. [Cladothrix Nutt., not Cohn.] 



1. T. lanuginosa (Nutt.) Standl. Annual; stems diffusely branched; 

 branches ascending or prostrate, 1-6 dm. long; leaf -blades rhombic-ovate to or- 

 bicular, entire, 0.5-2 cm. long; flowers in axillary clusters; bractlets obtuse; 

 utricle glabrous, included in the calyx. Cladothrix lanuginosa Nutt. Dry soil: 

 Tex. Kans. Utah Ariz.; Mex. Son. Jl-S. 



4. FROELICHIA Moench. 



Annual or biennial herbs, with woolly or silky pubescence and opposite, 

 entire or undulate leaves. Flowers perfect, subtended by 3 bracts, in dense 

 spikes. Calyx 5-lobed, woolly; tube longitudinally crested or tubercled at 

 maturity. Stamens 5, included; filaments united into a tube; anthers 1-celled. 

 Ovary 1-celled; styles short or wanting; stigmas capitate or brush-like. Utricle 

 indehiscent, enclosed in the tube of the filaments. 



Stout, 4-12 dm. tall: crest of fruiting calyx continuous, dentate. 1. F. campestris. 



Slender, 2-5 dm. high; crest of fruiting calyx interrupted, forming distinct spines. 



2. F. gracilis. 



1. F. campestris Small. Biennial or annual; leaves numerous and ap- 

 proximate below; blades spatulate to oblong or broadly linear, acute, white- 

 woolly beneath ; spikes 1-10 cm . long. F. floridana Coult. & Nels. , not Moq. Dry 

 or sandy soil: Minn. 111. Okla. N.M. Colo. Plain Son. Je-S. 



2. F. gracilis Moq. Annual or perhaps biennial; stem usually branched at 

 the base, 2-3 dm. high; leaves numerous near the base of the plant, often clus- 

 tered; blades linear-oblanceolate or linear-oblong, 1-5 cm. long, acute, white- 

 woolly; spikes 1-3 cm. long. Sandy valleys: la. Ark. Tex. Ariz. Colo.; 

 Mex. Plain Son. Jl-S. 



FAMILY 40. NYCTAGINACEAE. FOUR-O'CLOCK FAMILY. 



Annual or perennial herbs (all ours), usually with swollen nodes, and 

 alternate or opposite leaves, without stipules. Flowers regular, perfect, 

 often subtended by bracts forming a calyx-like involucre. Perianth simple, 

 corolla-like, campanulate or funnelform. Stamens 1-many. Pistil solitary; 

 ovary 1-celled, surrounded by the perianth-tube. Fruit indehiscent, angled, 

 ribbed, or winged. 



Bracts distinct. 



Fruit crested or winged; bracts in a whorl at the base of the head-like cluster; peri- 

 anth salverform. 

 Bracts conspicuous. 



Wings not completely encircling the fruit, interrupted above and below. 



l. ABRONIA. 



