Digitalis thapsi many characteristics of "D. purpurea" after four to five generations of cultivation, and that the former became indistinguishable from the latter, a report that was considered "probably" trustworthy by Charles Darwin. "D. thapsi" and "D. purpurea" hybrids are generally fertile. "Digitalis thapsi" is widespread in Spain. A biennial evergreen plant, it flowers in late spring. A study of the fruiting activity in "D. thapsi" showed that production, size and number of seeds were interrelated. Analysis has shown that seed weight is not related to the length of the cotyledon, and that the length of the fifth leaf can serve as
Orazio Comes experimentation in that sector. In 1958 the museum of the botanical institute of Portici, hosted in the Royal Palace, was named after him. Orazio Comes Orazio Comes (11 November 1848 – 13 October 1917) was an Italian botanist. From 1906 to 1917 he directed the Agricultural Higher Institute of Portici, in which, thanks to Vincenzo de Cesati, he begun teaching since 1877 as assistant of Nicola Pedicino for the chair of botany, to whom he succeeded in 1880. In his works he studied the physiology and plant pathology of Neapolitan mushrooms and agricultural plants, such as beans and tobacco. From