Sarracenia purpurea seeds, carnivorous purple pitcher plant
Sarracenia purpurea belongs to the family of the Sarraceniaceae, the pitcher plants. It is native to Northamerika and Canada. The plant occurs in marshy, boggy, moist areas. S. purpurea is also known as purple pitcher plant or northern pitcher plant. In Europe it is hold as an exotic ornamental plant. S. purpurea was also introduced in the Bavarian forest in Germany, where it is rated as an invasive species because it competes with local moss species.
The purple pitcher plant is, like one can suggest from the name purple in color. The venation of the pitcher gets dark red the older the plant gets. The pitchers are pubescent at the outer side. The pitcher that is in fact the leaf of the plant can reach a length of about 30 cm. S. purpurea differs from other species because it does not have a lid that stands horizontal above the opening of the pitcher. The lid of the purple pitcher plant is placed vertical at the pitcher. It is really necessary for S. pupurea that the lid is placed this way, because like this, rainwater can be collected and stored in the pitcher. Unlike other carnivorous plants S. purpurea synthesizes only few enzymes that can digest the insects. It would not be enough to digest the insect, or it would simple take too much time. Some bacteria that are included in the rainwater help the plant to digest the prey. To collect the rainwater very efficient the pitcher is bulgy at the ground. The inside of the pitcher is very smooth and though curious insects fall into the trap. S. purpurea synthesizes some substances that go into the rainwater and reduce the surface energy of the water. So the insects drown directly.
The flower of the purple pitcher plant stands clearly above the pitcher. The flower has an up to 40 cm long flower stalk. This long stalk avoids that the pollinators come near the pitcher and are trapped. This would not make any sense for the plant because it would lose the pollen the insect has collected. The flower is red and hangs down. This hanging down of the flower makes it easy for the pollinator to go inside the flower. With this tactic S. purpurea makes sure that pollen is collected.
The seeds of the purple pitcher plant are small, brown and have a nubby surface. The surface is also waxy. This makes the whole seed hydrophobic and it can be distributed with the water.
The seeds of Sarracenie purpurea need stratification before planting. If one does not stratify the seeds only few seeds will germinate. For stratification the seed should be put moist for 6 week into the fridge. After that they can be planted into the substrate. The substrate should be nutrient- poor and it should not include lime. The whole genus Sarracenia does not tolerant lime. The best germination success occurs when one uses Sphagnum moss as substrate. The stratified seeds in the substrate or the Sphagnum moss should be placed sunny and warm. At a temperature of about 20 to 25°C germination should occur after 4 weeks. S. purpurea is partly winter hardy.