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Jack & Jill-In-The-Pulpit

There are both male and female Jack-in-the-Pulpits, and nutrition determines which gender a given plant is.  For the first year or two, every Jack-in-the-Pulpit bears male flowers.  Then the amount of nutrients the plant takes up begins to influence the sex of the plant.  Females flowers produce seeds, and it takes a considerable amount of nutrients to do so.  Thus, if there’s an abundance of nutrients one summer, a plant is female the following summer; a lack of nutrients produces male Jack-in-the-Pulpits the following year.

While the flowers themselves are very distinct (females are green knobs, males are threadlike and not green), it can be hard to see them, as the spathe (pulpit) wraps around the spadix (Jack) which bears the flowers at its base. You can often guess the sex of a Jack-in-the-Pulpit by the number of leaves it has. In general, female plants produce two leaves, whereas male plants usually have only a single leaf.  If nutrients are really lacking, the plant typically produces a single leaf, but no Jack or pulpit. (Photo:  female Jack-in-the-Pulpit on the left; male Jack-in-the-Pulpit on the right).

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7 responses

  1. Pat Nelson

    Thanks for this post, Mary. It answered a LOT of questions I’ve had, but wasn’t quite sure I had. I think I still have more, but can’t reply further right now.

    May 27, 2020 at 10:11 am

  2. Allain

    I find today’s subject extremely interesting. Thank you, Mary. Never knew that.

    May 27, 2020 at 11:13 am

  3. Alice

    Since I was very little, I loved Jack-in-the Pulpits, but never knew any of that info! Thank you!

    May 27, 2020 at 12:17 pm

  4. kathiefive

    I have been noticing the incredible differences in size – some JITP’s are very small, maybe 6 inches tall, and some, like those in my slightly swampy place on the island are very large – maybe 18 inches tall. I wonder if these are different varieties or species, or whether they just are different sizes because of the conditions where they grow.

    May 27, 2020 at 6:31 pm

    • Hi Kathie,
      Great question. My best guess is they are the same species impacted by the availability of nutrients, etc. but I really don’t know for sure!

      May 27, 2020 at 10:06 pm

  5. Kathy d

    Thank you for this! I have these volunteering in several spots in my gardens, and they’ve been multiplying over the years. I noticed there were different colors but didn’t realize that gender was a factor. At the end of the season when the flowers wither I often see their berries, and then the following year there are tiny ones all clustered together where the berries fell, so I’ve been thinking that they must grow bigger as they get older. In my biggest patch I have all sizes of plants, flowering and not, and some of the flowering ones are absolutely huge (18″ tall), right next to tiny babies. I’m so delighted that they are thriving there. (And it’s full sun with dry soil! Who would have guessed!)

    May 28, 2020 at 9:20 am

    • Pat Nelson

      How lucky are you, Kathy! I think bears might get mine and that’s why they come and go and turn up in different places.

      May 28, 2020 at 12:47 pm

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