Skip to main content

Water plant maintenance

As most people know, plants absorb CO2 from the air and use it as a carbon source for building stems, leaves, and almost all of the other carbon-based molecules in the plant.  Plants also absorb oxygen from the air to produce energy and absorb water through their roots from moisture in the soil. It is important to allow enough air to get to plant roots. Too much water will drown the roots and starve the plant of oxygen. So it is curious to discover plants that have evolved to prefer their roots to be immersed in water. How do they survive? 

Today's assignment was to prune and clean some of the water plants in the tanks of the collection room #3, representing a subtropical climate. To address the question of how plants survive with very wet roots, I'll highlight two plants with different adaptations to wet feet.

Most of these plants in the two tanks of the subtropical room C3 have finished growing for the year and have entered domancy until spring. Winter is a good time to clean out the dead growth, repot overgrown plants, and control pests that may have invaded them. The two plants I'd like to highlight are the umbrella sedge, and the carnivorous crimson pitcher plant.

Water plants in the Collection room C3. Umbrella sedge in the mid-ground (Cyperus alternifolius)


Umbrella sedge

The umbrella sedge (Cyperus alternifolius) is one of many aquatic species in the large Cyperus family. It features a tall stem crowned by a radial array of leaflets (bracts) which resemble the spokes of an umbrella. Originally from Madagascar, it has become naturalized in many parts of the world. C. alternifolius has an extensive system of roots and rhizomes which help to anchor the plant in the water. The Cyperus genus has structural adaptations to trap air into special spaces in the stems and rhizomes (modified stems) allowing the use of more oxygen from the part of the plant above the water level rather than from the roots.

Today, I noticed the only pot of C. alternifolius in the collection had grown a root ball so large that it was breaking apart the plastic pot. I removed the pot and split the root into two parts; now there are two pots of the plant.

Crimson pitcher plant

Sarracenia leucophylla (the crimson pitcher plant), endemic to the southeastern areas of North America. This plant has evolved in wet boggy soils and marshes. The root system consists of rhizomes from which shallow roots arise. Rather than requiring nutrients to come from roots under water, the plant is carnivorous, and gets much of its nutrition from the insects it digests in its tall trap. The traps are modified leaves which arise from very short stems near the roots. In the spring, the plant sends up orchid-like flowers on separate spikes. There are several other unrelated plant species which, rather than roots, have evolved carnivorous traps of various designs which nourish the plant in very wet or nutrient poor soils.

The pitcher plants did not need repotting, just a bit of pruning back dead leaves and removing mealybug pests from the leaves and exposed parts of the roots.

Carnivorous Sarracenia leucophylla (crimson pitcher plant)


 

Labels:

Comments

Post a Comment

Popular posts from this blog

I celebrate learning this about cycad plants

I didn't know that the cardboard palm - Zamia furfuracea - is a cycad. It isn't a palm tree (don't judge me, I'm not a botanist). But it also doesn't look like the other more familiar types of cycads with their fluted upright palm-like fronds. I didn't know it is said to be the second most commonly cultivated cycad, after Cycas revoluta . I didn't know this plant is unrelated to the common ZZ plant - Zamioculcas zamifolia - although they have a similar appearance. Before today I didn't know any of these things, but now I am happy to have learned them. From the parking lot I walked to the U of M Conservatory greenhouse in near-zero F weather. Stepping into the tropical spaces was a joy of its own. But being able to learn new information and experience new procedures was a compounding factor. Joy squared. During my 3-hour volunteer shift, my initial task was to clean the parasite critters (mealybugs and scale) from the stems and leaves of the cycad, Zami...
Post a Comment
Read more

Mobile indoor green wall

Finally, after three years... my plant vines have grown and spread to be green wall that I had hoped for. I'm not sure it would have taken as long if the plants were in a more humid, sunny climate, et cetera. But given our indoor Minnesota location - even with a southwest exposure - the vines have needed that amount of time to climb the six feet from the base to the top rungs of the metal grid supporting them. The result has been worth the effort. And to be honest, I didn't have to wait three years to begin enjoying the green wall. The vines were already attractive when only half way up the trellis. A metal grid is filled with mix of Epipremnum aureum cultivar "Marble Queen", Epipremnum aureum aka golden pothos, and Philodendron Brasil . Architecture of the green wall The initial intent of the project was to grow a green wall, in an apartment, that could be moved around to be able to clean underneath, and also to provide a mobile room divider for our open-plan loft....
Post a Comment
Read more

Strung out in the greenhouse

The assignment for my four-hour volunteer shift at the University of Minnesota Conservatory greenhouse was clearly listed on a whiteboard, with my name attached. Since most of the tasks involved working with strings of overhead cables or air tubing, much of my shift was spent at the top of a ladder. Vining plants are limited to only a few of the many benches in the greenhouse. Steel cables are strung above the benches to support their growth. Because many plants grow in a small space, part of the challenge is to untangle and separate the vines so that they don't strangle each other. Not many of the vines are blooming at the moment, as it is winter. However, Thunbergia grandiflora is producing a few lovely blue flowers (its tendrils grow clockwise, hence the common name Bengal clockvine). It's a popular houseplant, but it has become an invasive weed in parts of the world, like Australia, especially around waterways. Thunbergia grandiflora; notice small brown scale insects sucki...
Post a Comment
Read more