Annals and Magazine of Natural History, 6(32): 144 (Oct 1850)
MONSTROUS FLOWERS OF PELARGONIUMS
William Sowerby

The following extract from a paper read by Mr. Sowerby at the Conversazione Meeting of the Royal Botanic Society, in the Regent's Park, describes an interesting case of monstrosity. After pointing out the distinguishing characters of the genera Geranium and Pelargonium, Mr. Sowerby proceeded to say: "The gardener, as in this case, when he finds nothing but external beauty to recommend a plant, endeavors, by selecting the most perfect, and then cultivating it highly, to increase in the succeeding both the beauty of colour and of form; and as the beauty of form depends on the same elements as that of colour, that is, as before explained, upon the indication of perfect adaptation to the end, or the resemblance of that indication, so a full round form is especially aimed at by the cultivator of flowers, and the Pelargonium fancier endeavors to obtain five broad and equal petals, to form a round flower, with the upper two deeply and brilliantly coloured, to produce a contrast to the three lower and light coloured ones; but with all his care the flowers do not come constant, and now and then one will play the truant, and sport as he calls it, and this commonly happens among the most petted or highest cultivated varieties. When the dark colour disappears from the upper petals altogether, and the petals become equal in size and form, it will be observed that the characteristic tubular nectary also disappears. The want of the nectary or honey tube is also accompanied by a regular arrangement of five anther-bearing and five abortive filaments. The white varieties are less liable to this change than those with rose or salmon-coloured petals, and it is also rare among the new fancy varieties; frequently it occurs in the central flower of the truss. In some flowers the nectary is also shortened, and in others a small spot will remain on one petal when the nectary is absent. In the fancy variety called Yeatmannianum grandiflorum, which has spots on all the petals, the spots become equal, the two large spots being reduced. An additional petal also accompanies the change in a few cases. One plant of the Beauty of Clapham, a rose-coloured variety, has almost every flower changed more or less. Thus it appears that cultivation makes one species of plant appear to run into another, and may destroy a remarkable generic character, consisting of the presence of an important organ in the flower, &c. Thus the gardener seems by over-cultivation to reduce his flower to a lower standard, but I do not think this is exactly the case; for though he may apparently reduce a Cape Pelargonium to a European Geranium in the eye of a botanist, or partly so, still he would have a more truly beautiful flower if he could obtain a full truss of beautiful large rose-coloured or pink flowers; we would recommend a trial of the seed from these sporting flowers."

Morphology of Flowers and Inflorescences (1981) p. 31
Focko Weberling

Pelargonium peltatum, III flower, medial cross-section, showing the hollow of the spur; IV base of a pedicel, with the cut spur tube showing above, and at D a swelling at the lower end of the spur tube, similarly in the bud which is about to opinion V.