NYCTAGINACKiE. (fOUR-O^CLOCK FAMILY.) 425 



Division III. APETALOUS DICOTYLEDONOUS PLANTS. 



Corolla none ; the floral envelopes in a single series (calyx) , 

 or sometimes wanting altogether. 



Order 84. NYCTAGINACE^E. (Four-o'clock Family.) 



Herbs (or hi the tropics often shrubs or trees^, witli mostly opposite and 

 entire leaves, stems tumid at the Joints, a delicate tubular or funnel-form 

 calyx ivhich is colored like a corolla, its persistent base constricted above the 

 1-celled 1-seeded ovary, and indurated into a sort of nut-like pericarp ; the 

 stamens few, slender, and hypogynous ; the embryo coiled around the out- 

 side of mealy albwnen, with broad foliaceous cotyledons (in Abronia mono- 

 cotyledonous by abortion). — Represented in our gardens by the Four- 

 o'clock, or Marvel of Peru (Mirabilis Jalapa), in which the 

 calyx is commonly mistaken for a corolla, the cup-like involucre of each 

 tlower exactly imitating a calyx. 



L Oxybaphus. Involucre of united bracts. Fruit wingless. Calyx bell slia}>ed. 

 2. Abronia. Involucre of distinct bracts. Fruit 5-\vinged. Calyx salver-forui. 



1. OXYBAPHUS, Vahl. 



Flowers 3-5 in the same 5-lobed membranaceous broad and (>])en iuvohicre, 

 whicli enlarges and is thin and reticulated in fruit. Calyx with a very short 

 tube and a bell-shaped (rose or purple) deciduous limb, plaited iu the hud. 

 Stamens mostly 3 (3-5), hypogynous. Style filiform; stigma capitate. Fruit 

 achene-like, several-nbbed or angled (pubescent in ours). — Herbs, abounding 

 on the western plains, with very large and thick perennial roots, opposite leaves, 

 and mostly clustered small tlowers. ( Name o^v^d(pov, a vinegar-saucer, or 

 small shallow vessel; from the shape of the involucre.) 



1. O. nyctagineus, Sweet. Nearly smooth ; stem becoming repeatedly 

 forked, 1-3° high; leaves all petioled (except the uppermost reduced ones), 

 from broadl If ovate to lanceolate, rounded or cordate or cuneate at base; inflo- 

 rescence loose and but slightly pubescent, the peduncles slender (at first soli- 

 tary in the axils) ; fruit ol)long-obovate, 2" long, rather acutely angled. — Minn, 

 and Wise, to Tex. and La. ; rare escape from gardens in E. Mass. and R. I. 



2. O. hirsutus, Sweet. More or less glandular-hirsute, especially about 

 the nodes and tlie usually contracted inflorescence, 1-3^^ high; leaves lanceo- 

 •ate to linear-lanceolate, sessile and cuneate at base or narrowed to a short 

 ))eti()le; stamens often 5 ; fruit with thickened obtuse angles. — Plains of the 

 Sask. to Wise, Iowa., Xeb., and Tex. 



3. O. angustifolius, Sweet. Often tall, glabrous except the more or 

 less liirsute peduncles and involucres ; leaves linear, thick and glaucous, often 

 elongated (2-6' long) ; fruit as in the last. — Minn, to Tex., and westward. 



2. ABRONIA, Juss. 



Involucre of 5-15 distinct bracts, enclosing numerous sessile flowers. Calyx 

 salver-form, with obcordate lobes. Stamens 5, included, adnate to tlie calyx- 

 tube Style included; stigma linear-clavate. Perfect fruit 3-5-winged. 



