196 SYSTEMATIC BOTANY. 



carpels many or few (rarely solitary), all distinct; seed peri- 

 spermic ; embryo small. 



Character. 



Thalamus convex or flat, often elongated, very rarely concave. 

 Calyx green or petaloid, regular or irregular (tig. 340) ; sepals 

 3-6, hypogynous, deciduous, occasionally persistent, usually im- 

 bricated in aestivation, sometimes valvate or induplicate. Corolla : 

 petals 13-15, distinct, hypogynous, in one or more rows, some- 

 times deformed (fig. 341) or wanting. Stamens indefinite, or 

 very rarely definite, hypogynous ; anthers adnate, bursting longi- 

 tudinally. Ovaries several or few, simple, 1-celled, distinct, or 

 very rarely coherent below to form a compound many-celled 

 ovary ; styles simple ; cells 1- or many-seeded ; placentas at the 

 ventral sutures ; ovules anatropous. Fruit : a collection of dry 

 achenes, a 1- or few-seeded berry, or a circle of follicles more or 

 less coherent below, bursting at the ventral suture ; seeds soli- 

 tary, erect or pendulous, or rarely horizontal in two rows ; 

 embryo straight, minute, in the base or within the apex of horny 

 perisperm (fig. 339). 



ILLUSTRATIVE GENERA. 



Tribe 1. CLEMATIDF^E. Mostly 

 climbing plants with opposite leaves. 

 Calyx valvate or i >i duplicate ; fruit 

 of achenes, usually surmounted by the 

 persistent and plumose style. 



Clematis, L. 



Tribe 2. ANEMONES. Calyx usu- 

 ally coloured, imbricated; achenes 

 sometimes tailed ; seed inverted. 



Thalictrum, Tournef. 



Anemone, Holler. 



Adonis, DC. 



Tribe 3. RANUNCULEJE. Calyx 

 imbricated ; achenes not tailed ; seed 

 erect. 



Ranunculus, L. 



Tribe 4. HELLEBORES. Calyx 

 imbricated ; petals irregular or none ; 



fruit of many-seeded follicles, more 

 or less coherent, rarely baccate. 



Caltha, L. 



Helleborus, Adam. 



Tsigella, Tournef. 



Aquilegia, Tournef. 



Delphinium, Tournef. 



Aconitum, Tournef. 



Act ae a, L. 



Tribe 5. PSONIE^:. Calyx im- 

 bricated ; petals Jlat or none ; carpels 

 forming dehiscent pods, surrounded at 

 the base by a disk. 



Pseonia, Tournef. 



Affinities and Morphological Structure. The typical floral formula 

 isS5P 5 fX; AGO oj G oo , the <xj indicating a spiral arrangement, with 

 vaiations, arising from suppression, multiplication, irregular growth, &c. 

 The characters which are almost universally found are the free sepals and 

 petals, the indefinite stamens, the inverted ovules, and the presence of 

 perisperm. None of these, taken separately, are absolutely characteristic of 

 the order, though collectively they are of the greatest importance. The 

 other characters are all more or less inconstant or variable, some of the 

 genera possessing them, others not. The conditions of the calyx and 

 corolla, and also of the ripe fruit, are not only normally very varied in 

 the different genera, but are readily affected and altered by cultivation. 



