BOTANY 



CALIFORNIA 



Division III. APETAL^. 



Floral envelope consisting only of a calyx (often petaloid), or wholly wanting. 



Order LXXVI. NYCTAGINACE^. 



Herbs (or rarely woody) with fragile stems and tumid joints, entire petiolate 

 exstipulate leaves mostly opposite and unequal, and perfect flowers with corolla-like 

 tubular to campanulate perianth, the persistent base indurated and constricted over 

 the 1-celled and 1-seeded free ovary; stamens few, hypogynous, with slender fila- 

 ments and rounded anthers ; style and stigma simple ; seed erect, anatropous, with 

 embryo encircling usually copious mealy albumen, the cotyledons foliaceous. — 

 Flowei-s with a calyx-like 3-5-cleft common involucre, often enlarging in fruit, or 

 with dilated and colored involucral bracts ; perianth plicate in aestivation. Stamens 

 often connate at base. Fruit consisting of the hardened base of the perianth, often 

 costate, striate, or winged, enclosing the free akene ; testa membranous. Embryo 

 in Abronia apparently monocotyledonous by abortion. 



An order of about 20 genera and 100 or more spcnies, nliiefly of temperate and tropical America, 

 exclusively so with the exception of Bnrrhanria and Pi.ionia, whicli are represented in tropical 

 Asia and Australia. Most of the United States species (about 40) are peculiar to the drier 

 interior region. The purgative and emetic qualities in the roots of many species are well known. 



Tkibe I. MIRABILE/E. Involucre calyx-like, 3-5-cleft or -parted, 1 - 12-flowered. Pcri- 

 antli tubular to funnclform or campanulate. 



1. Mirabilis. Involucre 5-lobcd, not chatigcd in fruit. Fruit not angled nor winged, and 



scarcely or not at nil ril)bcd. Stninens usually f>. 



2. AUionia. involucre deeply H-lobed, ^-flowered. Fruit with a double line of tulnircles on the 



back, surrounded by a rigid winged margin, toothed and inllexcd. Stamens usually 3. 



Tribe II. ABRONIEyE. Involucre of 5 or more distinct bracts, subtending a many-flowered 

 head. 



3. Abronia. Perianth salver-form, including the stamens and style. Fruit wing-angled. 



