I 



NYCTAGINACE.*:. (FOUR-o'cLOCK FAMILY.) 4'2o 



Division III. APETALOUS DICOTYLEDONOUS PLANTS. 



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

 or sometimes wanting altogether. 



Order 84. NYCTAGINACKyK. (Folr-o'clock Family.) 



Herbs {or in the tropica often shrubs or trees), with mostly opposite and 

 entire leaves, stems tumid at the joints, a delicate tubular or funucl-form 

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

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

 stamens fete, slender, and hypor/ynous ; the embryo coiled arowul the out- 

 side of mealy albumen, with broad foliaceous cotyledoJis (in Abronia mono- 

 ootyledonous by abortion). — Rej)resonte(l in our f^artlens by the Four- 

 o'clock, or Marvkl of Pkru (Miraijilis Jalapa), in which the 

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

 flower exactly imitating a calyx. 



L Oxybaphus. Involucre of united bracts. Fruit wingless. Calyx boll shajiwi, 

 '2. Abronia. Involucre of distinct bracts. Fruit 5-\vinged. Calyx salvcr-fi^nn. 



1. OXYBAPHUS, Vahl. 



Flowers .3 -.5 in the same .5-lobe(l membranaceous broad and open involucre, 

 which enlarges and is thiu and reticulated in fruit. Calyx with a very short 

 tube and a bell-shaped (rose or jini-ple) deciduous limb, plaited in the hud. 

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

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

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

 and mcjstly clustered small flowers. (Name o^ufidcpov, a viiifyar-saurer, or 

 small shallow ves.scl ; from the shape of the involucre.) 



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

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

 from broadli/ ovate to la7ireolate, rounded or cordate or ciniente (it liase; inflo- 

 rescence loose and hut 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 K. .Miuss. and I\. I. 



2. O. hirsutus, Sweet. More or less f/landular-hirsitte, esj>ecially about 

 the nodes and tlie usually contracted inflorescence, 1-3° high; leaves lunreo- 

 late to linear-iancfolale, sessile and cuneate at base or narrowed to a short 

 l)etiole; stamens often .5; fruit with thickened o])tuse angles. — Plains of the 

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



3. O. angustifblius, Sweet. Often taW, yiabroiis except the more or 

 le.ss hirsute peduncles and iuvcducres; leaves linear, thick and glaucous, often 

 elongated (2-6' long) ; fruit as in the last. — Minn, to '\\'\., and wt>stward. 



2. ABRONIA, Ju.ss. 



Involucre of 5 - 1 .') distinct bracts, enclosing numerous sessile flowers. Caly.x. 

 salver-form, with oljcordate lolics. Stamens 5, included, adnate to the calyx- 

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



