Sunday, October 27, 2013

Tree with Two Flowers

A group of blooming trees caught my eye near the local high school so I stopped to examine them. I really should get a bumper sticker that says “This car pulls over for strange plants and native flowers.” The plant turned out to be groundsel bush, Baccharis halimifolia.

What was particularly striking was that what appeared to be two different plants was actually the same species with male and female flowers on different plants (so, yes, technically they were two different plants). Baccharis is dioecious — male and female flowers are on separate plants.

Now we know plenty of dioecious plants (you do, really). Holly (Ilex) is one of the most common ones, but you need a hand lens to tell the difference between the male and female flowers on that one. Another example is fringetree (Chionanthus virginicus); that one is slightly more obvious if someone has already told you that the flowers are a bit showier on the male plant. Even then I think I’d need to see them side by side to recognize what “a bit showier” means.

Here is a whole page full of them: familiar names like juniper, persimmon, and willow are there. Dioecious plants are frustrating to gardeners that want fruit (like persimmon and hollies) but a blessing to those that don’t want it as well (think Gingko, a non-native tree with stinky female fruits).

Groundsel bush is considered a large shrub or small tree, growing up to 12 feet. As with many native plants, it has a delightful collection of common names: groundseltree, eastern Baccharis, sea-myrtle, consumptionweed, salt marsh-elder, and salt bush. The seeds on the female tree are very striking in the fall. I found one source that described them as “silvery, plume-like achenes” that resemble “silvery paintbrushes.” Here are some good pictures of the plant.

Mostly considered a plant of the coastal plain, apparently it is making its way more northward in the last few hundred years. Of interest is the fact that it is the only native species of the Asteraceae family that reaches tree size in the eastern US.

Groundsel bush is tolerant of saltwater spray so it is suitable for planting in beach communities or areas with brackish waters. In inland areas it is found in wet areas as well as disturbed places. Who knows how it got to this particular roadside near the high school? The plants are overhanging the sidewalk considerably so I expect a city crew will whack it back … and it will grow again next year.

I enjoyed discovering this new plant and learning more about it.

Sunday, October 20, 2013

Native Grasses: Beginning Thoughts

The subject of native grasses is surprisingly complex. I have been writing this blog for 3 years now and still feel inadequately prepared to discuss the subject. So I thought perhaps that I could do this in stages and share what I know and then build on that in future topics.

Seed heads

The first important distinction is the concept of cool and warm season grasses. Warm season grasses grow actively in the warm months (summer) and then flower and set seed in the fall. In the winter they are dormant. Examples of warm season grasses in Georgia include big bluestem (Andropogon spp.), little bluestem (Schizachyrium scoparium), Indiangrass (Sorghastrum nutans), eastern gamagrass (Tripsacum dactyloides), broomsedge (Andropogon virginicus), and switchgrass (Panicum spp.). 

Warm season grasses are the ones you see now with flowers (yes, they have flowers) and fluffy seed heads and attractive stem colors.

Poverty oats grass (Danthonia spicata) is just starting
new growth now; curly old foliage is distinctive

Cool season grasses are actively growing in the cool months. From what I can find, these are not likely to be used as ornamental grasses and in high heat they can actually go dormant – not what most homeowners want. Lawn fescue is an example of a non-native cool season grass and poverty oats grass (Danthonia spicata) is an example of a native one.

For those with wet conditions and perennial streams and rivers, there are native grasses that thrive there as well.

Enormously important in restoration areas, native grasses are often overlooked when people are looking to add plants to their landscape. Instead, people are swayed by non-native ornamental grasses, some of which are quite big (Miscanthus) and some of which can actually be invasive (Imperata cylindrica). There is some documentation that Miscanthus is also invasive in some areas.

Pink muhly grass (Muhlenbergia capillaris) at a nature center
In recent years one coastal plain native grass has gotten a lot of attention: pink muhly grass (Muhlenbergia capillaris). This grass is now commonly available in garden centers well outside it's native range and gets a lot of attention when planted in sweeping stands.

I think of it as one of the poster children for native plants. It helps raise awareness that native plants are beautiful in the landscape.

Other warm season native grasses are very attractive in the fall and pair nicely with fall perennials such as goldenrod (Solidago) and asters (Symphyotrichum). Little bluestem (Schizachyrium scoparium) is surprisingly common on roadsides and fields near me. The flush of red color in the fall and the movement of the blades in the wind are very attractive characteristics.

Splitbeard bluestem with goldenrod

Wildlife benefits are always important. There are Lepidoptera (skippers and brushfoots) that use native grasses for host plants. In addition, the seeds are eaten by small birds and small mammals that become food for larger birds (hawks and owls).

Cultivars of some of the native warm season grasses are becoming more available. Schizachyrium scoparium 'The Blues' is getting a lot of attention but there are other choices. If you are looking for a larger grass, look to switchgrass and the cultivars of Panicum virgatum.

Sunday, October 13, 2013

Fall Moves In

One of the things I like about Georgia is the extended warm season. Summer flowers continue past the official date of fall and fall flowers take us to almost winter. Yet natural signs of fall show up even with the flowers, many of them triggered by clues other than daytime temperature: crunchy leaves on the sidewalk, ripening seeds falling to the ground or puffing away on the wind.

Rhus copallinum, winged sumac

This week I noticed some of the signs that fall is moving in and realized I’d better appreciate this transitional moment while it’s here.

Some of the things that are leaving - leaves are dropping fast from the tuliptree (Liriodendron tulipifera) while the milkweed (Asclepias tuberosa) seeds are taking flight.
Liriodendron tulipifera

Asclepias tuberosa

Symphyotrichum racemosum

And some of the new things like pink muhly grass (Muhlenbergia capillaris) with a tiny white aster (Symphyotrichum racemosum) growing up through the base of it. Across the driveway, a seedling aster has sprouted.

Muhlenbergia capillaris

I can't believe I forgot to include this gorgeous blue fall flower in last week's post on fall flowers. Common names include blue mistflower and hardy ageratum, and I suspect that Conoclinium coelestinum has been a favorite pass-along plant since settlers first arrived. Adaptable and hardy and a bit enthusiastic, it makes a great spreader, especially in moist ditches.

Conoclinium coelestinum

Conoclinium coelestinum

Female bees are still collecting nectar and pollen this time of year and plants like the blue mistflower are important sources. Here is a picture of one coming in for a landing; notice the fat collections of pollen on her leg.

Clusters of berries await birds and other critters to discover them. I enjoyed watching a female cardinal eat some of the bright berries from the hearts a bustin' (Euonymus americanus) a few weeks ago.

Callicarpa americana

These white and purple beautyberries (Callicarpa americana) are ready for birds like mockingbirds and catbirds to find them.

And it wouldn't be October without something bright and orange, would it? These outrageously colored mushrooms caught my eye the other day on my walk. There was no way I could miss them. Enjoy fall at your place and be sure to notice the amazing natural world around you.