Friday Fabulous Flower - Kahili ginger

The Phactors are back home in Lincolnland greeted back from Hawaii by a snow storm, which is somehow fitting. So as jet lag wanes, and our lives get caught up, TPP is happy to be only one day late with the FFF. One of the more notable things about Hawaii biologically is, unfortunately, the prominence of invasive species. And none are more troublesome or more handsome than Kahili ginger (Hedychium gardnerianum), an ornamental species from Asia. This ginger forms almost impenetrable stands in the forest understory shading out native species.  And the massive rhizomes form dense mats preventing anything else from taking root.  In flower the 4-6' tall aerial shoots have terminal inflorescences of yellow-orange flowers that smell quite wonderful. The tan-colored fruits that follow are sort of nondescript until the fruits open revealing bright orange aril-covered seeds.  That's what's being shown in this image; flowers at the stage of seed dispersal.  Amusingly it makes the fern sort of look like an angiosperm.  The arils are both a visual attractant and a reward for the bird seed dispersers. So this plant can really get around.
Getting rid of such a plant is quite a chore, if not nearly impossible. Not knowing what is recommended, TPP suspects it takes cutting off the stand of aerial shoots, no small task, and then spraying the remaining stalks and rhizomes with an herbicide to prevent regrowth.  The idea of chopping out such a stand by hand sounds almost impossible, and reminds TPP of some of the worst gardening disasters of his experience on steroids. 

More research on invasive species

Having just started studying an invasive species, the most noticeable effects are a negative impact on some of the other plants in the community. This can happen via a lot of different mechanisms. But even if the invasive species is removed, they can have a residual negative effect from having altered the soil microbiota (link to a news article about such a study), something that has not been studied much. Sometime during the next month, in collaboration with a soil ecologist, samples will be taken from our long term study plots to determine what changes to the soil microbiota have resulted from this invading legume. This will be quite interesting because a related species is a native to the prairie, so will the change be observable, subtle, or dramatic? The data will tell.

Species diversity - Prairie community

Our census of species found in each plot of our study continues. So much fun to figure out one grass from another when they aren't in flower. But what's interesting are several general relationships. One, addition of mineral nutrients in a nutrient poor environment, reduces the number of species, more grass at the expense of forbs. Two, removal of a hemiparasite, a green plant that nonetheless is an obligate parasite, reduces the number of species, more grass at the expense of forbs. Three, the presence of a non-native, invasive species, increases the number of weedy species, and reduces the number of prairie species. A present the species census is about half done, and the Phactor hopes his back holds up, although in a rather counter intuitive manner, the tall vegetation plots are harder to do than the short stature plots, which differ by about a meter in height now.

The Princess tree - a royal pain?

A recent trip to the NYC area coincided with the flowering of the Princess tree, Paulownia tomentosa, also known as the royal paulownia or the empress tree. While those names suggest quite a blue blooded European pedigree, in actual fact this very attractive tree is from Asia. The genus is named after Anna Pavlovna, daughter of Czar Paul I, the eventual wife of Prince Willen of the Netherlands, so the name is what we call an honorific.

Paulownia is a very fast growing tree and you sometimes see ads in newspaper inserts touting it as a super-fast growing shade tree. And among trees, the princess tree is a real speed demon, growing to several inches diameter in just a few years, but this also means its wood is light weight and the trees tend to break easily and die young. So why was it imported way back in 1834? Well, in flower the princess tree is quite striking with its big panicles of large snapdragon like flowers.

And it makes lots of seeds, and they grow quite well in disturbed areas. The fact that princess tree is a woody invasive "weed" in some areas is not actually much of a problem there in the NYC area because where it grows, on railroad embankments, vacant lots, alleys, and the like ,means it covers up even worse looking stuff. However in areas of eastern TN and western NC this invasive tree is taking over road sides and rocky areas, and it has become so common many people think it a native. While the tree looks quite a bit like a Catalpa, it isn't a member of the bignon family, but sort of loosely related to some of the bits and pieces left over from the recent dismemberment of the snapdragon family.

So royalty or just a royal pain? Mostly the latter except when its flowering.