B. Papp szerk.: Studia Botanica Hungarica 32. 2001 (Budapest, 2001)

Erzberger, Peter: Ditrichum crispatissimum (Muell. Hal.) Paris, a new species of the Hungarian bryoflora, and Ditrichum flexicaule (Schleich. ex Schwaegr.) Hampe in Hungary

tissimum, but are still within the range of variability as indicated in FRISVOLL (1985), e.g. leaf length is rather short in the Hungarian specimen, but still at the lower limit for D. crispatissimum (see Table 1 in FRISVOLL 1985): a leaf length of 3.1-4.6 mm is given for D. fragilicuspis Dix. et Sainsb., a synonym of D. crispatissimum); the apical part of the subula is said to be frequently denticulate in D. crispatissimum, but sometimes almost entire; dorsal cells of the costa are usually shorter than adjacent lamina cells in D. crispatissimum, although FRISVOLL ( 1985) reports them to be sometimes more elongate in northern areas. C. Casas, who kindly examined part of the specimen, confirmed the correctness of the determination. A duplicate gathering (BP 68111) did not contain D. crispatissimum, only D. flexicaule s. str. However, these plants, as well as those included with the tuft of D. crispatissimum in BP 68244, were not typical D. flexicaule s. str., but showed certain character states of D. crispatissimum. They differ from the tuft of D. crispatissimum in the following respects. Plants of different appearance, less robust, of yellowish green colour, stem length 3-3.5 cm, in moderately dense tufts, matted with a moderate amount of tomentum except for the most recent apical growth, which is free of tomentum; short-leaved flagelliform shoots present. Dry leaves distinctly flexuose, spirally twisted subulae standing apart at stem apex. Vegetative leaves more or less gradually narrowed into subula, in some leaves sheathing base more distinctly contracted, (2.3-) 2.9-3.1 (-3.6) mm long, subula making up more than 2/3 of leaf length in some leaves, mostly about 2/3; cells of sheathing leaf base very variable in size and form, in upper part mostly 12 um long, some longer, in middle part (12.5-) 20 (-37.5) urn long, in lower part towards costa 18-35 urn, on average 29 urn long, rather broad (about 12 urn) and eporose to very slightly porose, but in some leaves reaching 50 pm length and more distinctly porose, cells in sheathing part form more or less straight rows, very few cells with curved walls; marginal border not well-developed, not more than one cell row broad, not grading into adjacent lamina, consisting of some thin-walled, more or less hyaline cells; auricles present in some leaves. According to these features these plants are referred to D. flexicaule s. str., but they approach D. crispatissimum in 3 characters, notably: leaf shape, subula length, and structure of basal cells. Judging from single stems of other bryophyte species included in these gatherings (Ctenidium molluscum in the tuft of D. crispatissimum only; Scapania calcicola in all tufts of D. flexicaule s. str. only), D. crispatissimum and D. flexicaule probably did not form a mixed stand at the Koloska rocks, because in that case they would be likely to have some bryophyte companion in common. This is of interest,