Tag Archives: reproduction

An Unexpected and (Re)Productive Study of the California Poppy

21 Mar

Sometimes, blown car tires lead to unexpected opportunities. While in California on our way to Monterey, our tire blew out on the freeway and very spectacularly separated itself from the rim. Our oldest son was driving and successfully steered the car to the side of the road, with the help of a kind truck driver, who stopped traffic in the right lane to let us over. While the spare tire was being put on, I noticed a cheery patch of poppies down a small hill, and headed there with my camera, whereupon I had an impromptu lesson in reproduction–of the floral kind.

The Golden State loves golden symbols, so it’s no surprise the California Poppy is the state flower. It’s a favorite of many gardeners, but also grows wild across California and elsewhere; masses of poppies make some Western mountains look as if they have been dusted with orange-yellow confetti. They also grow by the roadside, where I was lucky enough to get to study them for a little while. In that scraggly patch, there were poppies at all stages of development, from buds to full flowers, to seed pods.


The flower buds are encased in a calyx made up of two fused sepals; the papery cap slowly gets pushed off as the four overlapping poppy petals begin to unfurl.

  
Inside the cup-shaped flower itself are the stamens (pollen-tipped male reproductive organs) and the pistil (female organ), waiting for pollinators–usually bees, but also beetles and flies–to help ensure a new generation of Eschscholzia californica. This is the plant’s  very civilized (and somewhat passive) Plan A in terms of reproduction.


But, there’s a Plan B, too–and it’s a bit more lively. Once the poppy’s main flowering cycle comes to an end, the petals start dropping off, revealing an elongated seed pod (fruit) sitting on the disk-like torus. The pod gets longer and bigger, starts drying up in the sun, and finally bursts open, ejecting seeds as far as 6 feet away. This type of seed dispersal has a great name: explosive dehiscence.  Oh, how I wish I could have seen it in action.

  
So, what pollinators cannot achieve, the plant takes care of on its own, spreading its wealth just a bit further one seed pod at a time. Something to admire this April 6, which is California Poppy day.

 

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Sweetness or Deceit? Attracting Pollinators

28 Sep

Plants are wily, in their own ways. Some beguile with sweetness, others lure with deceit. This weekend at the United States Botanic Garden, I saw examples of both.

The Jamaican Poinsettia (Euphorbia punicea) takes the nicer approach. Below, you can see the brightly colored bracts, which are modified leaves, and a yellow, cup-like flower cluster called a cyathium. Insects are attracted to the clusters by the reddish-pink bracts and are then rewarded with the sugary nectar; in the photo, the glistening drops are almost overflowing from the cups. Arising from the center of the cluster is the pistil (the female reproductive organ), with three curved stigmas at the top, waiting to receive a dusting of pollen from the visiting pollinator.


Successful pollination leads to the development of a seed-bearing fruit. But if the plant has not been successfully pollinated, the fruit may wilt and never produce seeds.

Other plants, such as the Carrion Flower (Stapelia gigantea), attract pollinators by pretending to be (and smell like) something they are not: rotting flesh. You might think that if someone knows a flower smells like a decomposing mammal, s/he would avoid taking a sniff. But no. I partook of the putrid odor more than once, and can confirm that the flower does indeed smell vile. I pointed this out to other passersby, who also conducted repeated olfactory experiments of their own with identical results…. But back to the plant. In addition to its odor, this wrinkly and hairy flower is also meant to look like a decaying, oozing, leathery, peeling dead animal.


And boy, do some insects love that. Perfect spot to lay eggs, with plenty of food for the larvae, or so they think. They are mistaken; their reproductive efforts are futile. But they will have served their purpose: to help ensure the reproduction of the plant by taking and depositing pollen as they go about their business. A devious deception indeed. Here is a close up of the inside of the flower, complete with a green bottle fly circling around, and a pile of ill-fated eggs below.

 

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Weekly Photo Challenge: Spring

3 May

When I think of Spring, I think of flowers and new life.  This Tulipa “Ballerina” is one the the earliest and cheeriest flowers in my garden, and a look inside the tulip reveals some essentials about plant reproduction.


This close-up focuses on the three-lobed stigma (the top-most section of the tulip’s female reproductive parts, known collectively as the pistil), which catches pollen via its sticky and fuzzy surface. The pollen then travels down the tube-like style to the ovary where  fertilization takes place (if the pollen came from a tulip plant), ultimately leading to the production of seeds. The six pollen-covered anthers (the top-most parts of the male reproductive organs, known collectively as the stamens) are blurred in the background; the stamens emanate from the base of the pistil.

Tulips are considered “perfect” flowers because they contain both male and female reproductive organs. They can self pollinate, but can also cross pollinate in the wild with the help of bees and other pollinators. Alas, most commercial tulips, including this one, are sterile hybrids. But the good thing is that tulips also reproduce via their bulbs, which allows gardeners to enjoy them anew each spring.

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