An online resource based on the award-winning nature guide

Cardinal Flower Blossoming

You can’t get much redder than the red of Cardinal Flowers.  Their petals act as brilliant red flags beckoning Ruby-throated Hummingbirds, who favor red, to come drink their nectar (and at the same time, pollinate them).  Because their chief pollinator has wings and the ability to hover as it drinks, Cardinal Flower has no need for a landing platform, which most insect-pollinated flowers have.

Cardinal Flower has both male and female flowers.  Above the red petals is a red tube, at the tip of which the reproductive parts of the flower emerge.  First to appear are the male flowers, displaying pollen-bearing stamens.  After they die, sticky, Y-shaped pistils extend from the flower, ready to receive pollen.  The female flowers thus follow the male flowers (protandry).  These flowers mature from the bottom to the top of the spike and you often see both male and female flowers on the same plant (just barely discernible in pictured flower spike).

Male flowers produce more nectar than female flowers, and hummingbirds seem to know this, as they spend most of their time at the youngest, and therefore male, flowers on the top half of the flower spike.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.

7 responses

  1. Brenda S Metzler

    Perfect timing! Exactly a week ago I was visiting the Maine Coastal Botanical Garden in Boothbay Harbor and photographed a hummingbird drinking from cardinal flowers. It came while I had stopped to admire them and stayed for a full minute, moving from flower to flower – a lovely encounter.

    August 14, 2019 at 7:36 am

  2. Libby

    Do you know why some flower stalks bloom from top to bottom and other bottom to top, as with the Cardinal Flowers??? There is a practical reason and I don’t remember it!

    August 14, 2019 at 7:56 am

  3. janetpesaturo

    Beautiful photos, and a very interesting flower indeed. With a trail camera, I was able to observe exactly how hummingbirds pollinate it, and also saw that some hummingbirds are nectar thieves at cardinal flower. This surprised me, since the bird and flower are so perfectly matched for pollination. I am not sure why it happens, but happen it does.

    August 14, 2019 at 9:16 am

  4. Alice

    An unexpected sight of such red flowers, on a walk thru woodland trails & streams.

    August 14, 2019 at 12:14 pm

  5. botmom14

    Wow I hadn’t know about Lobelia’s protandry…I will have to look at the ones growing right outside my door.. thanks! Sent from my Samsung Galaxy smartphone.

    August 14, 2019 at 1:39 pm

  6. Sam

    You say, “First to appear are the male flowers” then later “the youngest, and therefore male, flowers”. Is this a typo?

    August 15, 2019 at 3:32 pm

    • No, no typo. The flowers are initially male, so when they first open and are at their youngest, they are male…hope this makes sense to you!

      August 17, 2019 at 3:11 pm

Leave a Reply to Mary Holland Cancel reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s