‘Mule’, hybrid, a type of plant monster which is engendered by putting pollen from one species of plant into the pistil or utricle of another.

If the organs of two plants two plants are similar, particularly their flowers, the pollen from one plant becomes impregnated with pollen from the second and the resulting fertile seed produces a new plant which is distinct from both. An example may be seen in Mr Fairchild’s garden at Hoxtan. [1]

This form of coupling in plants is quite similar to that of mares and donkeys which produces mules: the plants thus propagated have been given the same name and resemble these animals in that they cannot perpetuate the species. [2]

This operation effectuated on plants demonstrates how one can alter the properties and taste of a fruit by impregnating it with pollen from another fruit of the same class: for example, a pear with an apple, in which case the apple thus impregnated will keep longer and taste sharper. If wihter fruit is impregnated with the pollen of summer fruit it will go off more quickly. As a result of this accidental cross- pollination it can transpire that in an orchard in which there are different species of apple, fruit picked from the same tree differ in smell and maturation. It is from this spontaneous crossing that the prodigious variety of flowers and fruit which grow each day from seed originate. See Pollen and Seed.

Notes

1. In 1722, Thomas Fairchild (1667-1729) published The City Gardener, in which he explains his attempts at hybridization. His sterile ‘Fairchild’s Mule’ is the first recorded hybrid (1717): it was a natural cross between a carnation and a Sweet William of which both are species of Dianthus (articles ‘Fairchild’, Sandra Raphael, and ‘Hybridization’, William Thomas Stearn, in Jellicoe et al., 1991, pp. 183, 267).

2. ‘Mulet’ means mule. Before ‘Fairchild’s Mule’, the only known hybrids were of animals. The word ‘mule’ is still used in horticulture to refer to a sterile hybrid (ibid.; Huxley et al., 1992, iv.803).