POUR-O'CLOCK FAMILY. 283 



91. NYCTAGINACE^, FOUR-O'CLOCK FAMILY. 



Represented by a few plants with tubular or funnel-form calyx 

 colored like a corolla, and falling away from a persistent lower 

 portion which closes completely over the 1-celled 1-ovuled ovary 

 and seed-like fruit, forming a hard and dry covering which would 

 be mistaken for a true pericarp. Stamens 2-5, the long slender 

 filaments hypogynous, but apt to adhere somewhat to the sides of 

 the calyx-tube above. Embryo coiled around some mealy albumen. 

 (Lessons, p. 23, fig. 52-56.) Ours are herbs, with opposite simple 

 entire or wavy leaves, and jointed stems, tunid at the joints. 



1. ABRONIA. Flowers sm.ill, many in a pedunoled umbel-like head surrounded 



by an involucre of about 5 separate bracts. Calyx salver-shaped with a 

 slender tube, and a corolla-like 5-lobed border, which is plaited m the bud, 

 the lobes generally notched at the end. Stamens 5 and style included. 



2. OXYBAPHUS. Flowers small, a few together surrounded by a 5-lobed invo- 



lucre, which enlarges and becomes thin, membranaceous, reticulated, and 

 wheel-shaped after flowering. Calyx with a very short tube constricted 

 above the ovary, expanding into a bell-shaped 6-lobed corolla-like border, 

 open only for a day. Stamens (mostly 3) and slender style protruding. 

 Fruit (persistent base of calyx) akene-like, strongly-ribbed. 



3. MIRABILIS. Flower large, in the common species only a single one in the 



cup-shaped 5-cleft green involucre, which thus exactly imitates a calyx, as 

 the tubular funnel-shaped or almost salver-shaped delicate calyx does a 

 corolla. Stamens 5, and especially the style (tipped with a shield-shaped 

 stigma) protruded. Fruit ovoid, smooth and nearly even. 



1. ABB.OI9°IA. (Name from Greek word meaning delicate.) Western 

 North American herbs, cultivated for ornament : fl all summer. ^ 



A. umbell^ta, from coast of California, has prostrate slender stems, ovate- 

 oblong slender petioled leaves, and rose-purple flowers open by day, the invo- 

 lucre of small bracts. 



A. fr^grans, from Rocky Mountains, hardy N., has ascending branching . 

 stems, lance-ovate leaves, and white sweet-scented flowers opening at sunset; 

 the involucre of conspicuous ovate scarious and whitish bracts. 



2. OXYBAPHUS. (Name from a Greek word for a vinegar-sauca-, from 

 the shape of the involucre.) y Several species on Western plains : fl. rose- 

 purple, all summer. 



O. nyctagineus. Eocky or gravelly soil from Wisconsin W. & S. : 

 smooth or smoothish ; leaves petioled, varying from ovate to lanceolate, obtuse 

 or heart-shaped at base. 



O. dibidus. From North Carolina S. : often hairy above ; leaves sessile 

 or nearly so, acute at base, lanceolate or oblong ; fruit more hairy. 



3. MIRABILIS, FOUR-O'CLOCK or MARVEL-OF-PERU. (CIu- 

 sius called it Admirahilis, which Linuseus shortened. ) Natives of warm parts 

 of America : roots very large and fleshy ; leaves more or less heart-shaped, 

 the lower petioled ; flowers mostly clustered, showy, opening towards sunset 

 or in cloudy weather, produced all summer, y. 



M. Jal&pa. Cult, for ornament in many varieties as to flower (red, yellow, 

 white, or variegated), its tube only 2' long and thickish, stamens shorter than 

 its spreading border ; whole plant nearly smooth. 



M. longiflbra. Less common in cult. ; tube of the sweet-scented flower 

 6' long and clamray-hairj' (as well as the upper leaves) ; stamens shorter than 

 its spreading white border. 



M. Wrightiiina. ' Texas and cult. : more slender than the last, nearly 

 smooth, tube of the smaller and more slender faintly fragrant flower 4' long, 

 the border white tinged with rose ; stamens and style much protruding. 



