18 NATURAL ITISTORY OF PLANTS. 



GENERA. 



1. Mirabilis L. — Flowers regular hermaphrodite. Calyx petaloid 

 tubular or tubular-infundibuliform. Limb usually patulous, 5- 

 dentate, membranous-dilated between the teeth and induplicate con- 

 torted in the bud; tube slightly dilated at base and somewhat 

 constricted above dilatation ; upper part caducous. Stamens 5, un- 

 equal, even with or slightly longer than tube of perianth, alternating 

 with its teeth ; filaments 1-delphous at base, sometimes connate in a 

 short thick fleshy disk-like tube, free above ; anthers short 2-celled 

 laterally or subintrorsely rimose at margins. Ovary free above, sur- 

 rounded at base by a thin disk, 1 -celled ; style slender recurved at 

 apex ; summit globose divided into short simple or slightly ramose 

 capitellate stigmatiferous branches ; ovule 1, subbasilar suberect, 

 inserted in internal angle of the ovary, anatropous or subcampylo- 

 tropous ; micropyle anterior, inferior. Fruit (an achene or nearly a 

 caryopsis), clothed with hardened 5-agonal base of the calyx and 

 base of stamens ; internal albumen of suberect-seed farinaceous ; 

 cotyledons of incurvo-involute peripheral embryo incumbent, unequal 

 (the interior smaller) ; radicle cylindro-conical inferior. — Herbs ; root 

 usually tuberous-conical, stern and branches articulate at nodes ; 

 leaves simple opposite exstipulate ; flowers crowded in cymes at ends 

 of twigs (sometimes 1 -parous) ; involucre (sometimes calyciform) 

 formed of five large bracts connate at base imbricate or subvalvate, 

 sometimes 2 or 3-flowered {Acleisanthcs), or 1 -flowered {Eumirabilis, 

 Acleisanthes), or 3-oo -flowered {Quamoclidion). Flowers articulate 

 at base bej^ond involucre {Tropical and Subtropical Western America). 

 See p. 1. 



2? Nyctaginia Chois. — Flowers nearly of Mirabilis; calyx 

 tubular dilated at apex, 5-plicate. Stamens 5, much exserted. Style 

 even with stamens, germen and fruit of Mirabilis. — A herb ; leaves 

 opposite ; flowers terminal, falsely capitate, articulate, surrounded 

 by a polyphyllus imbricate involucre {Mexico). See p. 5. 



