Wednesday, June 6, 2012

Our native Magnolias

I had planned to go into much greater detail about Magnolias this spring, but found myself a bit caught off guard by our strange weather, which seemed to cause spring to not only come quick, but to also progress at a much faster rate than I would have anticipated. Most of our native Magnolias however flower in late spring or early summer, so were a bit protected from this. I'm probably not going to do a big entry like this for a while as gathering all the pictures I need takes quite a bit of time, but for now, we'll continue with one of my favorite genera, Magnolia.

Southern Magnolia (Magnolia grandiflora)
The Southern Magnolia (Magnolia grandiflora) is probably what would come to most people's mind when thinking of a native member of the genus. During my time living in New England I can only think of two or three which I saw growing at all, both in heavily protected locations and one of which had a noticeable yellow hue to the foliage throughout the winter months. It's for this reason I was a bit surprised to see the species flowering last week here in Delaware. Even though I'm now living in the range where these can be grown quite a bit more easily, I had still envisioned them as a species which flowered a bit later in the summer. Apparently, this is not the case. Still, it is an interesting plant not only for the large, white flowers, but also for its thick, leathery, evergreen foliage which on some plants has a heavy, brown pubescence to the underside. One of the hardiest cultivars, 'Bracken's Brown Beauty', has such a heavy pubescence the undersides of the leaves appear a dark brown in color, and is probably one of the best choices for those feeling courageous and wanting to grow the species in New England (I've also seen 'Edith Bogue' performing quite well).


Sweetbay Magnolia (Magnolia virginiana)
Up in New England, its much more common to see the Sweetbay Magnolia (Magnolia virginiana) in the landscape, though there is one wild population known in Massachusetts. It's considered to be "Semi-evergreen", as many leaves will often remain on the plant through the winter months. I've seen this vary immensely from tree to tree. The vast majority of plants I witnessed in New England would have few if any leaves present on the tree by February, probably 5% leaf cover at maximum, though there was one plant in Boston I remember being surprised to still have something like 75% cover even after a cold winter. When I moved to Delaware, as expected many of the trees held more leaves, and though the winter here was very mild this year, one plant seemed to still have nearly 90% leaf cover in the coldest week of January.
The flowers are quite nice as well, and though they are noticeably a bit smaller than that of the other Magnolias I'm describing here, they do tend to bloom for a longer period of time as far as I can tell. I've heard of their fragrance being described as somewhat lemony.

Cucumbertree (Magnolia acuminata)

The Cucumbertree is different from the above two species first as it is fully deciduous and thus holds no foliage over the winter months, and second, is one of only a few magnolias which is not considered to have a particularly showy flower. Personally, I find it to be quite interesting even if admittedly less attractive due to the waxy appearance and greyish, maybe blue-green color to the outside of the petals (defintley more green in the photo above). I'll actually often refer to it as my favorite Magnolia in order to be a contrarian, which is probably not much of a surprise to anyone who knows me personally. Anyway, the Cucumbertree is also quite important in Magnolia breeding as it is the source of the yellow color found in the flowers of many magnolia hybrids, such as 'Elizabeth', 'Butterflies', and 'Yellow Bird'. The name Cucumbertree is in reference to the fruit, an aggregate of multiple follicles which resembles a cucumber, especially before it has fully ripened. Other Magnolias also have an aggregate fruit, but it generally tends to resemble a cone-like structure, often seen on the ground with several red follicles emerging from the black rotting "cone".


Umbrella Magnolia (Magnolia tripetala)
Auriculate leaf base of Magnolia fraseri
And for comparison, Magnolia tripetala,
which lacks this base
The next two species, the Umbrella Magnolia (Magnolia tripetala) and the Fraser Magnolia (Magnolia fraseri) are very similar species and are often confused in the trade, but can be reliably distinguished from each other so long as you know what you're looking for. The base of the leaf blade of the Fraser Magnolia is auriculate, meaning it has two earlobe-like projections which extend towards the petiole (the stalk holding the leaf blade). The leaf of the Umbrella Magnolia has no such projections, instead narrowing to a point on either side of the blade. Both these trees flower quite nicely, with the Fraser Magnolia often having a flower which stands upright for a long period of time, whereas the Umbrella Magnolia has a flower which many find to have a rather disagreeable fragrance.


The Bigleaf Magnolia (Magnolia macrophylla) is a deciduous tree fairly similar to the above two species, but distinct enough that I credit it as being the tree that got me interested in botany and horticulture. When first seeing the plant, with its large undulating leaves spanning almost the entire length of my arm, as well as the huge flower buds that would soon open to reveal proportionally huge flowers, I found myself almost instantly questioning and challenging my perceptions on what a tree was. I'd always had a bit of an interest in plants, trees in particular, but it wasn't I saw this one that I really made it a point to learn more. I'd soon realize there was a lot more to plants than "the green things that don't move", and gain an appreciation for biodiversity which would alter my career and educational plans from that point on. Embarrassingly enough, I actually don't have all that many photos of it to share. I do however have a nice closeup of the closely related species Magnolia ashei (Ashe Magnolia), which is very similar though has a distinct purple blush towards the base of the tepals which the Bigleaf Magnolia lacks. The Ashe Magnolia is also interestingly endemic to (only found within) the Florida Panhandle, though it grows quite well when planted as far north as Boston.
Ashe's Magnolia (Magnolia ashei)
On a personal note, I'm finding myself wrapping up my first year of graduate school and still really enjoying the experience. I'm heading deep into doing my thesis research over the summer which looks to involve quite a bit of time in the library as well as some lab work, but I plan to still find some time to wander out into the gardens as well and hopefully get some photos of a few more plants that pique my interest.

2 comments: