Jour. Hort. Soc. London 2: 88-90
On Hybridization amongst Vegetables pt. 2
Hon. Rev. William Herbert, LL.D.
(Communicated Oct. 1846)

Gladiolus hybrids

Forty years ago I first crossed the large and brilliant scarlet and white Gladiolus cardinalis with the smaller, but more freely flowering, G. blandus, which sports with white, purple, and rose coloured flowers, and (under the name of carneus, which was in truth rather a local variety of the same) of a coppery flesh-colour. The result was a fertile breed of great beauty, of which the prevailing colour was purplish roseate.

Crossed again with cardinalis it yielded florid plants, scarlet, copper-coloured, rose-coloured, white, and purple with endless variation. By a cross of the first mule and of cardinalis itself with G. tristis, of which the flower is pale yellow with brown specks, deeper tints and rich speckling were introduced, with a difference in the foliage and seeds, the seed of G. tristis being smaller and longer, its leaves rigid and quadrangular, the transverse section exhibiting a cross. The seeds of cardinalis are like those of blandus, but larger.

There can scarcely be two species more dissimilar than cardinalis and tristis in any genus which has the form of the perianth uniform, the latter having such remarkable leaves, narrow, rigid, and erect, a slender stem, with night-smelling flowers, and the former very broad semi recumbent glaucous foliage, and an inclined half-recumbent stem with large scarlet and white blossom; yet the produce of these intermixed is fertile, and where the third species blandus has been also admitted into the union, it is fertile in the extreme (incomparably more so than the pure G. cardinalis), and by that triple cross the tall strong Gladiolus oppositiflorus of Madagascar has also produced offspring, which, though not disposed at present to make seed freely, has produced some this year.

Again, the first of these mules was fertilized by G. hirsutus (known at the Cape by the name roseus), a plant with flowers straighter than usual in the genus, and strongly scented, the leaves hairy and margined with red. That cross has not as yet proved fertile. The same G. hirsutus was crossed by Mr. Bidwill at Sydney, where the Cape bulbs thrive more freely than here, with G. alatus (which Ecklon wished to turn of into a genus Hebea), having hard rigidly ribbed leaves, a short stem, and orange flowers. The cross-bred plants flowered here last autumn, being intermediate in foliage and flower. The only opportunity I have had of crossing G. alatus with the first-named mules was defeated, notwithstanding much precaution, through the introduction of pollen by the humblebees, which are dangerous marplots to such experiments.

The showy G. Natalensis (called also Psittacinus) of the Natal country, which endures more frost than any of the Southern Gladioli, though it suffers much from July rains in many positions, has been freely crossed by myself, by Mr. Belfield, by Mr. Bidwill, and by cultivators on the Continent, with G. oppositiflorus, a Madagascar plant, found perhaps also in Caffraria, and often called improperly in the shops floribundus, an old name for a very different plant. The cross named G. Gandavi (for the adjective name Gandavensis to a garden cross is very objectionable) has been figured in the beautiful Ghent periodical work of M. Van Houtte and his fellow-labourers in botanic and horticultural science. It is there stated most erroneously to have been raised between Natalensis and Cardinalis. It flowered at Ghent for the first time in Europe, the soil and climate being much more congenial to Gladioli there than at Spofforth and in the west of England, but some of the seedlings raised in Devonshire and taken to Sydney had flowered earlier.

Abundance of beautiful seedlings have been raised here and abroad between cardinalis and oppositiflorus, and vice versâ, many of which have been sent over from the Continent under the name G. ramosus, as if they were plants of a natural species. Those from abroad have generally perished soon here, the soil and climate being too damp, but my own seedlings, probably the opposite cross, have a much stronger constitution, more variety of colour, and have this season ripened much seed. This statement might perhaps induce the reader to think all the species easily convertible; but it is not so. If I am asked why, I can only say, that the ways of God are not as our ways, and are past finding out.

The cross erroneously stated to have been made between G. Natalensis and cardinalis, if not absolutely impossible, is so difficult, that repeated attempts made during successive years by myself, and by J. Trevor Alcock, Esq., who interested himself in this matter, and probably by many others, have all proved abortive; and no cross has been effected, as far as I know, between G. Natalensis and any species from the Cape territory, although both Natalensis and the Cape species mix readily with the Madagascar plant.

I am now trying whether the cross G. Gandavi, being half-blood, will mingle with the Cape species, and the result is not yet quite certain. I lately set nine flowers of G. oppositiflorus with pollen of G. hirsutus. Large pods were readily produced, but unexpectedly they proved to contain only chaff and perishing kernels, the fertilization having perhaps extended to the seed-vessel and the outer coat of all the ovules, without having vivified them; but I believe one frosty night in August caused the failure. Five equally fine pods were produced at the same time on a scarlet 3/4 cardinalis mule. Few of their ovules were at all fertilized, and the greater part of those were chaff, but a few apparently good seeds were amongst them, which will probably vegetate.

G. Gandavi itself has ripened its seed three successive years, and one from the first batch of its descendants is now in flower. It preserves the cross-bred type, and might be accounted a distinct species, if I did not know that it was raised from oppositiflorus by pollen of Natalensis. It reverts, however, a little towards the male parent, the purple stripes of the female parent being less strongly marked than the original mules, and the flower is scarcely as large or bright coloured, following the course I have observed in other cases, that seedlings from a cross-bred plant by its own pollen sometimes degenerate in the size or brilliancy of their flowers.