William Herbert describes his Hippeastrum splendens as ‘Bis hybridum, Rutilo-Equestri-vittatum. - Splendid Knight's-star-lily, twice muled.’ He then provides a detailed description. ‘In consequence of a confusion of labels I have some doubts whether the female parent of these mules was produced from Vittatum by the pollen of Reginae or of Equestre. Its flower was of a very bright scarlet with a white star, and having been deprived of its anthers and impregnated by the dust of Rutilum, it produced 50 or 60 seedlings, most of which have now flowered, varying a little in shape and colour, and some of them scarcely distinguishable from Rutilum, except by a little vestige in the mouth of the tube of the beard, which is derived from the two other species. The flower which is represented was amongst the brightest of the seedlings, but no painting can approach the splendour of the natural hue. One alone of them had the coroll considerably larger. The coroll of Mule Amaryllideae seems to follow the size of the male parent, which might indeed have been expected, since the coroll bears the filaments, and therefore belongs to the male portion of the flower. The strong scent of Vittatum is entirely lost in this second cross, all the seedlings having proved scentless, like Rutilum, with which they also conform in the production of an infinity of offsets, but the offsets are not blind or dormant, like those of Rutilum. They flower freely in a cool greenhouse, appearing to be as hardy as Vittatum, and will doubtless succeed well out of doors. The leaves are narrower than those of Vittatum, and they will bloom in a much smaller pot.’ [Herbert’s Appendix p.52/1821].In his Amaryllidaceae Herbert briefly reports in great length on the early hybridisation experiments with Hippeastrum. [Herbert p.141 and elsewhere].