THREE SPECIAL CASES OF FERN HYBRIDS: 



the range of form to be found among natural populations of sporophytes. Thus Haracic 

 in 1893, who appears to have been the first person to study natural populations of the 

 plant, described three different morphological types and figured two of them under the 

 names of forma typica, var. Reichardtii (Milde's original specimen) and var. lobata. 

 Some additional evidence was added by Ivancich in 1923, who reinvestigated the ranges 

 of form and spore fertility among natural populations. Haracic's var. lobata was not 

 examined again, since it had been found only on the island of Osiri which Ivancich 

 did not visit. Haracic's forma typica was, however, described as the most stable, and 

 his var. Reichardtii as the most unstable. In addition, three other varieties were described, 

 namely, var. hemionitifolia, which closely resembled Scolopendrium hemionitis, var. erosa 

 which differed from forma typica in having large basal lobes and more irregular outline 

 to the rest of the lamina, and lastly var. ceterachifolia which very closely resembled 

 Ceterach. This last 'variety' was in effect only one individual plant, since it was sterile 

 from spores and could only be propagated from the rhizome. By means of it, however, a 

 series of fronds could be shown which almost entirely bridged the gap between one genus 

 and the other. 



This history has been given in some detail partly because Scolopendrium hybridum is 

 somewhat unfamiliar to most botanists, but also because it differs from all the other 

 suspected fern hybrids in combining characters not merely of two different species 

 but of two different genera whose close relationship might not otherwise be suspected. 

 It is thus clearly a plant of quite unusual interest, and I am extremely fortunate in 

 having had access to living material of it. This has been of several kinds, all, however, 

 ultimately referring to the one island of Lussino. The first material to reach me con- 

 sisted of a pot of tiny sporeling plants raised by the late Dr F. W. Stansfield and presented 

 to me after his death by his son. The origin of the pot was described by Stansfield in the 

 British Fern Gazette (vol. vii, p. 91, 1936) as follows: 'A spore-bearing frond was sent to 

 M. Kestner [of Lausanne] from the island of Lunin [accidental misreading of Lussin]. 

 M. Kestner brushed off some spores and raised plants from them and, mainly from that 

 fact, he formed the opinion that it was not a hybrid but a species per se. He afterwards 

 sent on the frond to me and I was able to collect from it a few more spores which 

 I sowed and have now about a dozen tiny plants as the result.' These plants grew to 

 maturity and were the main source of cytological material. They were, however, 

 supplemented, shortly before the war, by two consignments of adult plants very kindly 

 suppHed by Professor Lona of Trieste. The first consignment consisted of one plant of 

 forma typica which had been in cultivation in Trieste Botanic Garden, and later, in 

 1938, some additional plants of various morphological kinds, though not including the 

 extremes (var. hemionitifolia and var. ceterachifolia), were sent direct from the island of 

 Lussino. Owing to the outbreak of hostilities the cytological study of this material was 

 less exhaustive than it would otherwise have been ; the fresh collections were, however, 

 invaluable in confirming the vahdity of the results obtained with the Stansfield material. 

 During the war itself almost the entire collection was lost, but spores saved from the 

 last surviving individual have re-estabHshed the culture. A silhouette of the dry spore- 

 bearing frond, together with that of a living leaf of the next generation obtained from it, 

 have already been shown in Fig, 145 a and b. They resemble somewhat the description 



144 



