Golden Protector

I’ve always planted marigolds among my garden. I’ve heard these orange beauties have protective properties against herbivores. Is it true?

Hmm. Most researchers have found properties released from marigold roots inhibit bacteria, fungi, and/or nematodes (although this is extremely variable, depending upon the part of the plant used, how the marigolds are grown, and the pest species tested).

Most interesting sidetrack from my search… some research shows inhibition of Plasmodium, the microscopic organism that causes malaria (1).

Thanks to Charlie O’Shields of DoodleWash for the #WorldWatercolorMonth inspiration.

1. Pankaj Gupta & Neeru Vasudeva (2010) In vitro antiplasmodial and antimicrobial potential of Tagetes erecta roots, Pharmaceutical Biology, 48:11, 1218-1223

The Corpse Flower Opens – and Stinks!

Many flowers use insects to transfer pollen from one plant to another. Some flowers attract bees or butterflies. The corpse flower, though, uses carrion beetles and flesh flies. What attracts these pollinators? The color of decaying flesh, putrid scents, and the warm temperature of a freshly dead body. Lovely.

While we humans tend to focus on color, beetles and flies who pollinate the corpse flower may be more attracted to the scent and temperature. Angioy et al. (2004) showed that certain insects have the abilities to “see” temperatures and are attracted to heat. The heat generated by the spadix of the flower is unusual in the plant kingdom. Not many plants expend tons of energy to warm up to around 100 degrees Fahrenheit. Those few that do are called “thermogenic plants.” It’s generally accepted that the heat increases the range of the odors (Barthlott et al. 2009), which is true of course. But wouldn’t all plants benefit by increasing scent ranges? Yet this mechanism is found in plants that only mimic carcasses to attract pollinators – plants like the skunk cabbage and voodoo lily.

While most flowers give their pollinators a reward of some kind (think nectar), the corpse flower seems to just take, take, take. The plant mimics carrion, where pollinators normally lay their eggs, yet gives the pollinators no food or reward. Or could it?

I personally found it interesting that the spathe of the corpse flower closed back up after it bloomed. It’s probably protecting the developing fruit. Yet the fruit takes 6-9 months to mature. At the Chicago Botanic Garden, the spathe of their corpse flower wilted after about 3 months, exposing yet unripe fruit. Could the flower serve as protection for the developing carrion beetles? Is there any food supply for those youngsters when they hatch? Or is it just a dead end (pun intended)?

FYI: while other arums smell like corpses too (my personal favorite is the “pig-butt arum”), some species of Amorphophallus smell like bananas or carrots.

1. Angioy AM et al. 2004. Function of the heater: the dead horse arum revisited. Proceedings of the Royal Society Biological Sciences. 271(3) S13-15.
2. Barthlott W et al. 2009. A torch in the rain forest: thermogenesis of the Titan arum (Amorphophallus titanium). Plant Biology 11. 499-505.

The Corpse Flower, a Botanical Marvel

It’s rare to see a corpse flower bloom. If you ever have the opportunity, take it… especially if you get to visit Sumatra. Lucky for me, a corpse flower (Amorphophallus titanium) blossomed in the greenhouse next to my office last weekend at NC State University (https://cals.ncsu.edu/corpse-flower-at-nc-state/).

It took the corpse flower, dubbed Lupin, 13 years to save up enough energy to bloom.  It’ll probably be another five years before it does so again. So corpse flowers are rather special. Actually, fewer than 200 cultivars have been recorded since 1889. But now’s your opportunity. For some yet unknown reason, a bunch are flowering at once (1).

Lupin grew six feet tall in under two months! That tall, purple-grey phallic structure is called a spadix. At its base are about 700 vibrant orange and purple female flowers and thousands of male flowers (2). When the one giant petal (actually a bract known as a spathe) opens, the spadix releases a stench to attract carrion beetles and flies who pollinate all those female flowers.

So actually, the corpse flower isn’t a flower at all. It’s over a thousand flowers wrapped into one giant, stinky, gorgeous inflorescence.

1. http://www.sciencealert.com/no-one-really-knows-why-but-america-s-corpse-flowers-are-all-blooming-at-once
2. Gandawijaja, D, S. Idris, R. Nasution. 1983. Amorphophallus titanium Becc.: a Historical Review and Some Recent Observations. Ann. Bot. 51:269-278.

Wildflower Stories: Part 1

The wildflowers along the Appalachian Trail impressed the heck out of me during a recent hike. My inner biologist began counting the number of plant families represented. The artist inside distracted my count with constant “ooo, pretty!” comments. This drawing highlights just a few of the flowers from the trip – and launches the first of a host of posts.

 AGRIMONY (Agrimonia sp.)

Once upon a time, Agrimony was a go-to herb for the local physician. It was reported* to cure or alleviate eye and liver problems, intestinal troubles, back pain, gunshot wounds, snakebites, sore feet, pimples and coughs. The most horrifying treatment combined Agrimony with “a mixture of pounded frogs and human blood, as a remedy for all internal haemorrhages.”¹

We’ve come a long way (thank you, Scientific Method). While Agrimony may contain compounds beneficial to our health, rigorous controlled studies are lacking or do not show the benefits claimed above. Still, Agrimony is sold today as an herbal remedy.

A lack of data doesn’t mean Agrimony won’t help ailments – it doesn’t mean it will either. As a member of the Rose family (the flowers’ many stamens clued me into its familial origins), Agrimony shares traits with apples, lemons, nectarines, almonds, and of course roses. So it’s in good company with a lot of wonderful foods that offer beneficial properties and nutrients.

*This blog does not endorse the use of Agrimony to treat any of these ailments.

1. A Modern Herbal by M. Grieve. 1971. Dover Publications, New York.

Mocking Berries

My yard is full of Strawberries – crawling across the patio, creeping over the lawn, growing around the a/c unit. Too bad they’re all fakers.

Delicious Wild Strawberries bloom white flowers that develop drooping mini-versions of the strawberries we know and love. The Mock Strawberries (Potentilla indica) growing in my yard, in comparison, display yellow flowers and upright little red fruits so tempting to behold. It’s like the little plant begs, “Look at this beautiful, juicy berry. Don’t you want to eat it?” Unfortunately, the fruit is totally flavorless. Just a tiny little ball of seeds and water. The little jerk-plant “mocks” us.

There may be hope though. Mock Strawberries came from India or south Asia where they’re called She Mei (Snake Strawberry). Apparently, the plant is used to control mosquito larvae in China (1959 Compendium of Chinese Indigenous Pesticides). I’m not quite sure how that works, but I’ll be conducting my own experiments this summer. If successful, I won’t feel so betrayed.

Spring has SPRUNG!

Daffodils (Narcissus poeticus) bring true joy to the winter-weary world.
But after a few moments of appreciation, what does a biologist do? Dissect it!

The showy parts of the plant consist of tepals (the petal-like structures) and a corona (the trumpet-shaped form that defines a daffodil). Growing from the center of the flower are the stamen with pollen-laden anthers and the style, leading down to the ovary.

If you decide to dissect your own daffodils, wash your hands afterward. The plants contain a mildly toxic substance – mostly to fend off herbivores like deer or insects. And if you just want to admire cut daffodils on your coffee table, keep them in their own vase. That toxin can harm other flowers too.

That daffodil is no pansy!