The Gardener’s Magazine 13: 633 (Dec. 1841)
Propagation by Leaves
(W. Herbert, in Gard. Chron. for 1841, p. 381.)

You requested me to state in writing, the success which I had many years ago in raising certain monocotyledonous plants from the leaf. In the year 1809, I first tried to raise bulbs of a Cape ornithogalum, by setting a cutting of a leaf. The leaf was cut off just below the surface of the earth, in an early stage of its growth, before the flower-stalk had begun to rise, and it was set in the earth near the edge of the pot in which the mother plant was growing, and so left to its fate. The leaf continued quite fresh, and, on examination (when the bulb was flowering), a number of young bulbs and radical fibres were found adhering to it. They appeared to have been formed by the return of the sap which had nourished the leaf. Thereupon two or three leaves more were taken off and placed in like situations, but they turned yellow, and died without producing any bulbs. It appeared to me then, and it was confirmed by subsequent experience, that, in order to obtain a satisfactory result, the leaf must be taken off while the plant is advancing in growth. I found it easy thus to multiply some bulbs that did not willingly produce offsets. I afterwards tried, without cutting the leaf off, to make an oblique incision in it under ground, and in some cases just above ground; attempting, in fact, to raise bulbs by layering the leaf. This attempt was also successful; and some young bulbs were formed on the edge of the cut above ground, as well as below. I tried cuttings of the stem of some species of Lilium, and obtained bulbs at the axil of the leaf, as well as from the scales of the bulb; and that practice has been since much resorted to by gardeners, though I believe it originated with me. I raised a great number of bulbs of the little plant which has been successively called Massonia, Scilla, and Hyacinthus corymbosus, by setting a pot full of its leaves, and placing a bell-glass over them for a short time. A bulb was obtained with equal facility from a leaf of a rare species of Eucomis; and experiments with the leaves of lachenalias were generally successful. I apprehend that all liliaceous bulbs may be thus propagated; but the more fleshy the leaf, the more easily the object will be attained.