The Morphological Features and Biology of a Relict and Endangered Woody Plant Species: Chamaedaphne calyculata (L.) Moench (Ericaceae)

Plants (Basel). 2019 May 15;8(5):129. doi: 10.3390/plants8050129.

Abstract

Chamaedaphne calyculata (L.) Moench is a rare post-glacial relic, which reaches the south-western boundary of its European range in Poland. However, little is known about the morphology and biology of this species. In this study a biometric analysis of assimilating leaves and general morphological appearance was carried out; flowering, fruiting, and seed production in a natural site were described and the ability of seed germination was determined after varied seed storage time at 0-2, 2-4, 6-8, and 21-23 °C. A quite large intrapopulation variability was found as regards the features under analysis. The most varied features included the length of the petiole, followed by the leaf blade area, while the length to the width of the leaf blade was the least varied feature. C. calyculata flowered abundantly and about 50% developed flowers turned into fruits. On average there were 56 seeds per fruit with a predominance of mature seeds. The length of the seed storage time had a significant effect on all parameters of the germination process. The temperature at which the seeds were stored, apart from the time to maximum germination parameter, had a significant effect on other parameters of the germination process. Interactions between the seeds storage time and temperature factors were observed only for germination percentage, germination index, and germination index rate parameters. The ability of seeds to germinate, non-creation of the seed bank and other results of the research provide new information necessary for planning and carrying out conservation procedures (including active conservation in ex situ conditions).

Keywords: Ericaceae; leaf morphometrics; protected plant; seed germination.