Drosera capensis (Cape Sundew) Propagation by Leaf Cutting Video Summary Chlöe Fackler PLNT 310, April 7th, 2017

Sundew Natural History Sundews (Drosera spp.) are carnivorous plants in the family Droseraceae, which also contains the genus Dionaea (Venus Flytrap) and Aldrovanda (Waterwheel) (Lloyd, 1942). They employ a sweet and sticky nectar, secreted from the tentacles (trichomes) on their leaves, to trap insects (Finnie and van Staden, 1993). They then curl the leaf to completely encapsulate their prey, and digest it using a variety of enzymes. The reason for their carnivorous nature is to supplement their growth in mineral-poor media with nitrogen and other nutrients extracted from their prey. In particular, D. capensis, the Cape Sundew, is a species of subtropical sundew native to the cape of

South Africa (Brittnacher, n.d.). It can be propagated by seed, and Cape Sundew (Drosera capensis) Plants in the Raymond Greenhouse by leaf, root, and inflorescence cuttings, as well as in vitro using micropropagation. Growing it is also fairly simple, requiring a moist, salt-free medium of peat/sand and sphagnum, and significant light.

Objective To determine the effectiveness of different media and the use of Stimroot No. 1 rooting powder (IBA 0.1 mgL-1) on the growth of Drosera capensis (Cape Sundew) from leaf cuttings

Procedure View the corresponding video for step-by-step instructions on how to conduct this experiment, or propagate sundews by leaf cuttings in general. Required Materials • Healthy Drosera capensis specimens • Scissors • Isopropanol (for sterilizing) • Sphagnum • Distilled water • Containers with holes (for growing the cuttings in sphagnum moss) • Containers without holes (for growing the cuttings in distilled water) • Seedling flats • Flat covers -1 • Stimroot No. 1 (IBA 0.1 mgL ) • Labels (for recording significant data about each of the treatments)

Results and Discussion

Trial A (# of Trial B (# of Average (# of Plantlets) Plantlets) Plantlets)

Sphagnum/No IBA 13 6 9.5 (n=10)

DH2O/No IBA (n=10) 10 22 16

Sphagnum/IBA (n=10) 5 1 3

DH2O/IBA (n=10) 8 3 5.5 Number of Plantlets per 10 Leaf Cuttings by Treatment and Trial

Of the four treatment combinations tested, the pure distilled water proved to be the best in promoting and maintaining plant growth, with an average of 16 plantlets per 10 leaf cuttings without the IBA. This could be due to the fact that the pure distilled water did not harbor pathogens, compared with some of the other treatments. The pure sphagnum moss came in second, with an average of 9.5 plantlets per 10 leaf cuttings without the IBA. While sphagnum has bacteriostatic and fungistatic properties that would aid in hampering pathogenic growth, it would seem that it provided a less suitable environment than the pure distilled water (Brittnacher, n.d.). Both media treated with IBA powder did considerably worse than their pure counterparts, at only 3 plantlets per 10 leaf cuttings in the sphagnum with IBA, and 5.5 plantlets per 10 leaf cuttings in the distilled water with IBA. It is possible, since IBA is an auxin and promotes root, not shoot, growth, that the addition of the hormone did little, if anything at all to help the growth of new plantlets (Finnie and van Staden, 1993). It might even have negatively affected the cutting growth, if it contained any pathogens. In the future, it might be interesting to see if the addition of a different type of plant hormone, such as a cytokinin like benzylaminopurine (BAP) that stimulates shoot growth, might change the outcome of the experiment.

Left: Cape Sundew (Drosera capensis) Leaf Cuttings Right: Cape Sundew (Drosera capensis) Leaf Cutting Sprouting Plantlets

Acknowledgements Thanks to Danielle Donnelly for supervision and suggestions towards this project, as well as Guy Rimmer and Hawaiian Botanicals for help in acquiring the materials to work with. Additional thanks to Ian Richie for tracking down the containers with which to grow the cuttings in, and Sophie Thibodeau and Christie-Anna Lovat for moral support. Finally, thanks to Raina Fan, who gave solid advice on video editing and production.

About the Author Chlöe Fackler is a U2 environmental biology student, specializing in plant biology and minoring in anthropology. She is most interested in topics concerning plant and fungi systematics, as well as ethnobiology, especially of native and naturalized Texas species.

References Cited Finnie, J.F. and J. van Staden. 1993. XII Drosera spp. (Sundew): Micropropagation and the In Vitro Production of Plumbagin. In: Medicinal and Aromatic Plants V. Y.P.S Bajaj (ed.). Springer Berlin Heidelberg, Berlin, Germany. 164-177 pp. Lloyd, F.E. 1942. The Carnivorous Plants. Chronica Botanica Co. Waltham, Massachusetts. Brittnacher, J. n.d. ttp://www.carnivorousplants.org/howto/Propagation/DroseraLeafCuttings.php Accessed Jan. 18 2017.