CLXXVII. NYCTAGINE^E. 



627 



Mirabilis. Diagram. 



Mirqhilu. Androecium. 



Pisonia, Fruit. 



Pisonia amkafa. 

 Fruit cut transversely (mag.). 



diclinous (Pisonia}, axillary or terminal, solitary or aggregated, rarely in a simple 

 spike, umbel, cyme or panicle; floral bracts 6, sometimes ovate or lanceolate, free 

 or united, often forming a calyciform much dilated coloured involucre larger than 

 the flowers ; sometimes 1-3, minute ; involucre calyciform, herbaceous, sometimes 

 monophyllous, 3-5-toothed, l-5-.flowered, and often enlarged after flowering ; some- 

 times polyphyllous, many-flowered. PERIANTH petaloid, tubular or tubular-cam- 

 panulate or infundibuliform, variously coloured ; the lower part of the tube hardest, 

 sometimes striate, always persistent, enveloping the fruit and accrescent, the upper 

 part resembling a corolla ; limb membranous, folded in aestivation, rarely marcescent, 

 usually falling after flowering. STAMENS hypogynous, fewer or more than the 

 divisions of the perianth, 8-30, rarely equal in number, sometimes unilateral ; fila- 

 ments filiform, often unequal, included or exserted, inflexed in aestivation, free, or 

 coherent at the base, sometimes even adnate below to the perianth- tube ; anthers 

 introrse, 2*-celled, globose, dehiscence longitudinal ; pollen of globose large granules. 

 OVARY free, sessile or sub-stipitate, l^carpelled, 1-rcelled ; style terminal or sub-lateral, 

 simple, involute in aestivation ; stigma simple, pointed or globose, straight or coiled, 

 sometimes branched or penicillate, multifid ; ovule solitary, erect, sessile, micropyle 

 inferior. ACHENE membranous, included in the hardened tube of the perianth. 

 SEED erect, testa adherent to the endocarp. EMBRYO usually curved or folded, rarely 

 straight (Pisonia) ; cotyledons foliaceous, enveloping a farinaceous albumen, or coiled 

 upon themselves, and scarcely separated by a mucilaginous albumen (Vieillardia) ; 

 radicle inferior. 



[The following is Choisy's arrangement of the genera in De Candolle's 

 c Prodromus ' : 



TRIBE I. MIRABILE.&. Involucre calyoiform, 1, or many-leaved. *Mirabilis, Quamoclidion, 

 *0xylaphu, Abronia, Acleisanthes, Pcntacrophys, &c. 



TRIBE II. BUGINVILLE.E. Involucre bract-like; bracts large, dilated. *Biiginvillea 



(Bougainvillea), Tricycla, ? Cephalotomandra, 



TRIBE III. BOERHAAVIE^. Salpiantlms, Pisonia, Neea, Vieillardia, Boerhaavia. ED.] 



ss 2 



