NYCTAGINACEAE (FOUR-O'CLOCK FAMILY) 375 



dark-purple, ripe in autumn. Low grounds and rich soil, s. Me. to Ont., Minn., 

 and southw. July-Sept. 



NYCTAGINACEAE (FOUR-O'CLOCK FAMILT) 



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 which is 

 colored like a corolla, iti persistent base constricted above the l-celled }-seeded 

 ovary and indurated into a sort of nut-like pericarp; the stamens few, slender, 

 and hypogynous; the embryo coiled around the outside of mealy albumen, with 

 broad foliaceous cotyledons (in Abronia monocotyledonous by abortion). Rep- 

 resented in our gardens by the FOUR-O'CLOCK or MARVEL OF PERU (MIHABILIS 

 JAL\PA), in which the calyx is commonly mistaken for a corolla, the cup-like 

 involucre of each flower exactly imitating a calyx. 



1. OXYBAPHUS L'He"r. 



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 

 mostly clustered small flowers. (Name 6vpd(pov, a vinegar-saucer, or small shal- 

 low vessel; from the shape of the involucre.) ALLIONIA Loefl. 



* Leaves all petioled except the uppermost reduced ones. 



1. 0. nyctagfneus (Michx.) Sweet. Nearly smooth ; stem becoming re- 

 peatedly forked, 0.3-1.5 m. high; leaves broadly ovate, cordate ; inflorescence but 

 slightly pubescent ; pedicels slender, becoming 1 cm. in length, the lower axillary, 

 solitary, the upper crowded upon short floral axes ; involucres at length very 

 large, 2 cm. in diameter ; fruit cylindric-obovoid, 4 mm. in length, rather acutely 

 angled. Man., Minn., and Wise, to Tex. and La. ; also introd. eastw. The 

 leaves vary to oblong or ovate-lanceolate and abrupt or even cuneate at the base. 



2. 0. floribundus Chois. Similar but with mostl} 7 narrower ovate to oblong 

 leaves (not cordate) ; involucres smaller and more numerous, glomerate upon 

 the elongated branches of an open cymose panicle ; pedicels short, seldom over 

 6 mm. in length. (O. nyctagineus, var. oblongifolius Gray; Allionia ovata 

 Pursh, not O. ovatus Vahl.) "O.," Mo. (Bush), southwestw. and northwestw. 



* * Leaves sessile or nearly so. 



3. 0. hirsutus (Pursh) Sweet. More or less glandular-hirsute, especially 

 about the nodes and the usually contracted inflorescence, 3-9 dm. high ; leaves 

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

 short petiole ; stamens often 5 ; fruit with thickened obtuse angles. (Allionia 

 Pursh; A. bracteata Rydb. ; Calymenia pilosa Nutt.?) Plains of the Sask. to 

 Tex., Wise., O. (Louth), and casual eastw. in N. Y. and Ct. 



4. 0. albidus (Walt.) Sweet. Similar but smoother; stem whitish ; leaves 

 oblong, elongated, obtuse ; flowers in weak individuals few, axillary, in stronger 

 ones numerous in a terminal panicle. (Allionia Walt.; A. lanceolata Rydb.) 

 Kan. and Mo., S. C. and Tex ; occasionally adventive northeastw. 



5. 0. line^ris (Pursh) Robinson. Often tall, glabrous except the more or 

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

 elongated, 5-15 cm. long. (0. angustifolius Sweet; Allionia linearis Pursh; 

 also A. Bushi Britton, a low form.) Minn, to Mo., Tex., westw. and north- 

 westw. ; established on sandy ground, North Haven, Ct. (Evans). 



