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ORDER CXXIX. NYCTAGINACEiE. 



Calyx coroUiue, tubular j variously coloured, often con- 

 stricted in the middle : lower part harder - and sometimes 

 ribbed or striated, always persistent and enclosing the fruit : 

 upper part bearing the corolla, seldom withering, usually de- 

 ciduous : flowers hermaphrodite or dioecious (in Pisonia) by 

 abortion : stamens definite, hypogynous, often connate at the 

 base, and closely withering round the ovary, sometimes ad- 

 herent to the base of the ovary, seldom free, exserted, un- 

 equal: filaments thin, elongated, sterile ones shortened: 

 anthers 2-celled, cells round, large, often separated, and as 

 if bound by a connectivum : bracts at the base of the flowers, 

 sometimes ovate or lanceolate, free or connate, forming a 

 calyx-shaped involucre round the flowers, sometimes ovate- 

 dilated, larger than the flower, coloured, sometimes very 

 minute, I — 3 to each flower, deciduous or persistent : invo 

 lucre sometimes gamophyllous, 3 — 5-teethed, 1 — 5-flowered, 

 often spreading after flowering, sometimes polyphyllous, many- 

 flowered, the number of leaves definite or indefinite : bracts 

 dilated-coloured, usually threefold, surrounding sometimes 

 a single flower in the middle, sometimes 3 flowers, namely, 

 one seated on each bract, the peduncle co-adunate to the 

 bract : ovary free, single, elongated, 1-ovuled : style simple, 

 terminal or lateral : stigma simple, acute or globose, straight 

 or revolute, branched or even pencil-shaped : fruit surrounded 

 by the base of the perianth, hardened and increased, smooth 

 or ribbed, striated, filling it or leaving an empty space : 

 achenium simple, testa membranaceous : embryo incurved, 

 in Pisonia straight : radicle inferior : albumen white, mealy, 

 copious. — Trees, undershrubs, or herbs : branchlets axillary, 

 sometimes abortive, and then forming' spines : leaves seldom 

 alternate or scattered, the leaf belonging to the spine or 

 branchlet or axillary peduncle abbreviated, petioled, entire or 

 waved: flowers glomerate, seldom on a spike or umbel, 



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