554 
RANUNCULA CEAE 
developing in descending order. In Nigella sp. and others, after the 
terminal fir. is formed, the buds below develope in ascending order, 
so that a raceme with an end fir. is formed ; in Aconitum &c. the 
same thing occurs, but the terminal fir. rarely developes. In Nigella, 
Ranunculus acris. Floral diagram of axillary dichasial cyme, with details of 
primary flr. Sta. according to the A phyllotaxy. a j8 bracteoles of primary, 
* 0', a, j8 / of later, firs. After Eichler. 
Anemone, &c., there is an involucre of green leaves below the flr., 
usually alternating with the calyx. 
The flr. itself is typically spiral upon a more or less elongated 
receptacle, but frequently the leaves of the perianth are in whorls. It 
is usually regular and g . The perianth is usually petaloid and rarely 
(eg. Ranunculus) shows a true calyx and corolla. Frequently there 
occur nectaries of various patterns between the perianth proper and 
the sta. ; these are usually considered as modified petals, but it is as 
probable that they are derived directly from sta. without having passed 
through the petal stage. An interesting series of transitions may be 
seen by comparing the following firs. : — Caltha (honey secreted by 
cpls., ‘calyx’ present, nothing between it and sta.), Helleborus or 
Eranthis (honey secreted in little tubular ‘petals’), Nigella (ditto, but 
‘petals’ with a small leafy end), Ranunculus auricomus (‘petals’ 
distinct and coloured, with pocket-like nectary at base), R. acris &c. 
(petals large, nectary at base). In Aconitum and Delphinium there 
is a zygomorphic flr. The sta. are usually oo and spiral, the anthers 
extrorse; the cpls. oo, apocarpous, spiral, with either one basal or 
several ventral anatropous ovules. In Nigella the cpls. are united; 
there is only i in Actaea, which thus forms a link to Berberidaceae. 
As a rule the firs, are protandrous and the sta. , as their anthers 
open, bend outwards from the centre of the flr. A good series of firs, 
showing various grades of adaptation to insects may be found in R. 
(cf. pp. 87 seq.), e.g . Clematis (pollen flr.), Ranunculus (actino- 
morphic, honey scarcely concealed at all), Nigella (honey in little 
closed cavities), Aquilegia (honey in long spurs), Delphinium (ditto, 
but zygomorphic also, and blue in colour), & c. 
