four-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. 15, fig. 36, 37.) Ours are herbs, with opposite simple 

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



1. ABRONIA. Flowers small, many in a peduncled umbel-like head surrounded 



by an involucre of about 6 separate bracts. Calyx salver-shaped with a 

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

 the lobes generally notched at the end. Stamens 6 and style included. 



2. OXYBAPHUS. Flowers small, a few together sun-ounded 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 5-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. 

 a. 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. ABRONIA. (Name from Greek word meaning delicate.) Western 

 North American herbs, cultivated for ornament : fl. all summer. 2/ 



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-saucer, from 

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

 purple, all summer, 



O. nyetagineus. Rocky or gravelly soil from Wisconsin W. & S. : 

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

 or heart-shaped at base. 



O. ^Ibidus. 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. (Clu- 

 sius called it Admirabilis, which Linnaeus 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. Jl 



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 clammy-hairy (as well as the upper leaves) ; stamens shorter than 

 its siireading white border. 



M. Wrighti^na. Texas and cult. : more slender than the last, nearly 

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

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



