NYCTAGINACE^:. (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 in the tropics often shrubs or trees), with 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 l-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 albumen, 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 

 flower exactly imitating a calyx. 



1. Oxybaphus. Involucre of united bracts. Fruit wingless. Calyx bell-shaped. 



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



1. OXYBAPHUS, Vahl. 



Flowers 3 - 5 in the same 5-lobed membranaceous broad and open involucre, 

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

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

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

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

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

 and mostlv clustered small flowers. (Name b^vfidtpov, 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 broadly ovate to lanceolate, rounded or cordate or cuneate at liase ; inflo- 

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

 tarv in the axils) ; fruit oblong-obovate, 2" loug, 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 the usually contracted inflorescence, 1-3 high; leaves lanceo- 

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

 petiole ; stamens often 5 ; fruit with thickened obtuse augles. Plains of the 

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



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

 less hirsute 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 the calyx- 

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



