Better Botanical Bureau

Monday was the first full day of the Botanical Society of America meeting. SVSU has been well represented by Tori Ott, Joshua Brandel, and Jeneva Tomaszewski.

Here is the SVSU group at the 2023 Botanical Society of America meeting in Boise, Idaho. It is good to be attending in-person meetings again.

This is the time of year leaves are changing color from green to red, orange, or yellow. Yellow and orange (and sometimes bright red) colors come from carotenoid pigments. Deep red colors come from flavonoid pigments.

During the growing season chlorophyll is present in dense amounts in leaves. There are other pigments in leaves as well, but these are in smaller quantities and are masked by chlorophylls, so the leaves appear green. Cooler temperatures and shorter days in autumn trigger the end of chlorophyll production. The chlorophyll that is present begins to break down and valuable parts of chlorophyll are reabsorbed by the plant. The other pigments are then revealed as the leaves turn color.

The best autumn colors are typically seen when there is a combination of bright light and cooler temperatures. Some of the bright reds in autumn colors comes from flavonoid pigments that act as sunscreen in the leaves. Bright light and cooler temperatures both increase conditions where light damage can occur in leaves, increasing the need for some of these pigments.

Have you ever noticed the groove on a plum or peach fruit? It is formed during development of the fruit.

All fruits come from maturation of the o***y in a flower. In the case of a plum or peach, a single carpel made the o***y. Developmentally (also evolutionarily), a carpel is a modified leaf. Imagine the modified leaf being rolled into a tube, with the edges meeting each other and sealing together to form a cylinder. This is a carpel. In the case of a plum or peach, you can see where the carpel edges met in the form of a suture, obvious on the mature fruit as a groove on one side.

Many of us are accustomed to seeing mosses, especially if you live in wetter locations. (Drier conditions make it difficult for mosses to reproduce.) The next time you see a moss, look closely. The green “fuzz” that you see is actually many individual moss plants that are standing side by side. They are small, but they are packed together tightly, producing an appearance of a green carpet. Potentially you will also see some brown structures growing up out of the green carpet. What you are seeing are the two generations in the life cycle of the moss.

Mosses, like all plants, have an alternation of generations life cycle. There is a haploid generation called the gametophyte and a diploid generation called the sporophyte. Gametophytes produce gametes and sporophytes produce spores. Both generations are easy to see in a moss. The green “fuzz” are the gametophytes. The gametophyte is the dominant generation in nonvascular plants like mosses. The brown structures that are taller are the sporophytes. The sporophyte is the dominant generation in vascular plants, but it is smaller in nonvascular plants.

How many petals are on a carnation flower? Ask any botanist, and she/he will (correctly) answer five.

Although most people associate the name “carnation” with the many-petaled version, the many petals on horticultural carnations are a product of selective breeding by people. Prior to that, carnations only had five petals. You still see this in some kinds of carnations. The genus of carnation is Dianthus. If you go to a nursery and buy a flower called “Dianthus,” you will be getting the wild type of carnation, with five petals.

About 75% of flowering plant species (perhaps as many as 90%) rely on animals for pollination. Flowers have been shaped by many generations of pollinators. Animal pollinators have preferences; sight, smell, placement, and time-of-day are all factors. When pollinators prefer certain appearances, smells, times, etc., these are the individual plants that reproduce the most, meaning these are the characteristics most likely to be passed to subsequent generations. Following many generations of pollinator preferences, flowers have been shaped to be attractive to whatever pollinates it.

Around 500 species of angiosperms are pollinated by bats (528 species in 67 families in 28 orders, according to a 2009 survey), primarily in warmer places, i.e., tropical and subtropical areas of the Old and New Worlds. Bat pollinated species include banana, mango, Agave, and some cacti.

Bats feed on nectar, fruit, or pollen. In fact, about a quarter of all bat species include these in their diet. Bats are endothermic, with high metabolic rates. To attract bats, these flowers produce lots of nectar. Blooming time and placement are also important. Among the New World bats that pollinate flowers, most of them forage at night. Accordingly, bat-pollinated flowers open at night, with the bats attracted by scent. The smell is like something fermenting or musty. Bats use echolocation to navigate their way to flowers. To facilitate this, bat-pollinated flowers are commonly placed out in the open, either on the top of tall stalks or hanging down below foliage.

As bats visit flowers, they primarily eat nectar. They have long tongues, sometimes with a brush-like tip and their front teeth may be reduced or lacking. Transfer of pollen occurs as bats feed on several flowers. Bats make excellent pollinators, as they are highly mobile organisms that can transfer pollen long distances.

If you are in a northern state like Michigan, the best time to seed a lawn is around Labor Day. Perhaps work within a window that starts a couple of weeks before Labor Day and goes a couple of weeks after Labor Day. We are past the hottest part of the year; the pairing of cooler nights with warm days works well for seeding.

Consult your county or state extension service for specific dates or species that work well in your area. Northern states will likely be around now, whereas southern states might recommend a little later in the year. Northern states will likely recommend “cool season” species like fescue or bluegrass. Southern states will likely recommend “warm season” grasses like buffalo grass or Bermuda grass. Specifics will vary by location, but some general advice and suggestions include:

Measure the area to be seeded (e.g., in square feet) and use recommended amounts of seed, fertilizer, and (if needed) lime. There are additional challenges that come from using too little or too much of any of these.

Determine grass species that will work well for your area. Consider amount of water, amount of sun/shade, and climate.

When considering your lawn/yard, try to contribute toward responsible stewardship of resources. Do not pump lots of water to keep cool-season grass green in a dry setting. If you are in a hot or dry area, consider warm-season grasses or xeroscaping.

Also try to contribute toward responsible ecology. When possible, grow native species for your area.

During germination and early stages of growth, seeds and young seedlings are in shallow soil. This is also the part of the soil that dries the quickest. Sprinkle it often enough to keep the soil surface moist, but try to avoid puddles of standing water.

Recognize it can take some time for a seeded lawn to establish. Be patient with the initial “thin” look of the grass and realize there might be some weeds that grow too.

About 75% of flowering plant species (perhaps as many as 90%) rely on animals for pollination. Flowers have been shaped by many generations of pollinators. Animal pollinators have preferences; sight, smell, placement, and time-of-day are all factors. When pollinators prefer certain appearances, smells, times, etc., these are the individual plants that reproduce the most, meaning these are the characteristics most likely to be passed to subsequent generations. Following many generations of pollinator preferences, flowers have been shaped to be attractive to whatever pollinates it.

Although most people think of flowers attracting pollinators with “pretty” flowers, there are functional pollinators out there that have different preferences. For example, flies pollinate many flowers. Think about the things that flies seem to like and imagine the flowers that would be successful in attracting flies.

Flies are attracted by flowers that mimic the smell of rotting flesh. For example, “carrion flowers” and skunk cabbage employ this strategy, as do the co**se flower and some others. Showy flowers or bright colors are not needed, but the smells from fly-pollinated flowers are quite important. If it does not mimic the right smell, flies will not be attracted to it. Indeed, these flowers have perfected this smell over many generations of evolutionary fine-tuning.

About 75% of flowering plant species (perhaps as many as 90%) rely on animals for pollination. Flowers have been shaped by many generations of pollinators. Animal pollinators have preferences; sight, smell, placement, and time-of-day are all factors. When pollinators prefer certain appearances, smells, times, etc., these are the individual plants that reproduce the most, meaning these are the characteristics most likely to be passed to subsequent generations. Following many generations of pollinator preferences, flowers have been shaped to be attractive to whatever pollinates it.

Some birds pollinate flowers, particularly hummingbirds. Metabolic rates in hummingbirds are high, so flowers need to provide a hefty reward to attract hummingbirds. Indeed, hummingbird-pollinated flowers usually produce a lot of nectar.

Most birds have a poor sense of smell, so the flowers they pollinate have little scent. Instead, flowers attract them with visual cues. Hummingbird-pollinated flowers are usually bright red and trumpet shaped. Usually hummingbirds hover when they visit flowers, so there is no need for a landing spot on the flower. To allow for this, stamens in these flowers are long and touch part of the bird, e.g., its forehead. Pollen is transferred to the next flower when a stigma is also extended from the flower.

To attract hummingbirds in temperate latitudes, plant something with red flowers that produces nectar. Several species of Salvia (sage) work well for this. More options are available in warmer climates. For example, some cacti attract hummingbirds. In these pictures, we see a hummingbird visiting flowers on a hedgehog cactus in Arizona.

About 75% of flowering plant species (perhaps as many as 90%) rely on animals for pollination. Flowers have been shaped by many generations of pollinators. Animal pollinators have preferences; sight, smell, placement, and time-of-day are all factors. When pollinators prefer certain appearances, smells, times, etc., these are the individual plants that reproduce the most, meaning these are the characteristics most likely to be passed to subsequent generations. Following many generations of pollinator preferences, flowers have been shaped to be attractive to whatever pollinates it.

If flowers are looking to attract a nocturnal pollinator, they open at night. Moths are common nocturnal pollinators. Flowers attract moths by a combination of sight and smell. Moth-pollinated flowers are usually white and bloom at night. Sometimes the name of the plant reflects this, with examples like evening primrose or moonflower. Often these flowers have strong scents emitted at night to attract the moths. In some cases, these flowers are also selective in who they let pollinate them. The flowers are often tubular, so only long-tongued moths can reach the nectar, as is seen in to***co.