Rhizoidal tubers and protonemal gemmae in European Ditrichum species

Abstract

The occurrence of rhizoidal tubers and protonemal gemmae in European Ditrichum species is described in plants collected in nature and compared with protonemal gemmae and tubers obtained in agar culture. Rhizoidal tubers are reported for the first time in D. pallidum, D. plumbicola, D. subulatum and D. zonatum and earlier reports on tubers in D. cylindricum, D. cornubicum, D. heteromallum, D. lineare and D. pusillum confirmed. Based on the occurrence and morphology of tubers, the European species of Ditrichum may be subdivided into four groups.