A new sex annotation for flowering plants

I know a few annotators that do not use the sex annotation for plants (me included) and I suspect there are others. For reference, the current sex annotation consists of three mutually exclusive values:


  1. Cannot Be Determined: Cannot be determined from the evidence provided
  2. Female: Evidence indicates that organism can produce ova for use in sexual reproduction
  3. Male: Evidence indicates that organism can produce sperm for use in sexual reproduction

The previous annotation may be adequate for animals but it is not particularly useful for annotating the majority of plants. To compensate, it has been suggested that the value Bisexual be added to the current sex annotation. Doing so would probably make things worse since the previous annotation is used for both animals and plants. I think we need a new annotation just for plants.

The terms “female plant” and “male plant” are only relevant for a small percentage of flowering plant species. In general, it’s better to talk about flowers, not plants. This leads to the following annotation with four non-mutually exclusive values:

Floral organs

  1. Female flowers: At least one flower with female parts only
  2. Male flowers: At least one flower with male parts only
  3. Bisexual flowers: At least one flower with both female and male parts
  4. Sterile flowers: At least one flower with neither female nor male parts

The previous annotation expresses the full range of options without introducing new terminology. Using it, observers will quickly learn that sexual reproduction in flowering plants is much richer than in animals. Unfortunately I don’t know enough about non-flowering plants to generalize the annotation to other plant groups.

Note that the old values Female and Male port directly to the new values Female flowers and Male flowers. The values of Cannot be Determined are ignored since a use case for that data is not known.

Comments are welcome.


Would this replace the “sex” option entirely? If so, a problem I can imagine for a truly dioecious species is that if you have something like a persimmon tree with fruit, the tree is female but there aren’t flowers to annotate about, so it doesn’t quite fit your definitions.


There currently is not a sex annotation for flowering plants, so this would be new and not replace an existing annotation.

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My angiosperm observations currently have “Flowers and Fruits”, “Leaves”, and “Sex” available under the annotations.


Currently? Sex annotation for plants was restored after a break for a few days.


Fruit should be included as it is evidence of female parts unless the goal is to only assess plants in flower.

“Cannot be Determined” should be included as that shows if the observation has been assessed or not and lets you filter those out as already annotated. Many observations will not have flowers or fruit.

Also, I think many (most?) male flowers have sterile female parts and many (most?) female flowers have sterile male parts.


Definition from Oxford Languages
monoecious: (of a plant or invertebrate animal) having both the male and female reproductive organs in the same individual; hermaphrodite

I guess it depends what manner of displaying the data is the most useful.

I had omitted fruit in my suggestion in the other thread because there is a separate annotation for fruit and all dioecious plants with this annotation can be assumed to be female.

So the information would be there, but divided between multiple annotations.

One difficulty is that both female and bisexual flowers can produce fruit, and as far as I know it isn’t possible to tell whether a fruit is a result of a female flower or a bisexual flower. In most cases this will depend on the reproductive system of the species in question. But there are a few flowering plants (e.g., Silene) that may have both hermaphroditic and female plants (gynodioecious) or species that may have female and bisexual flowers on the same plant (gynomonoecious).

For non-botanist iNatters - that mostly means - I dunno! I would not rely on that, unless the person who annotated is someone who knows plants well.

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I’d thought of that, but it seems like a lot of the people who really use the sex annotations are using them for dioecious species, so removing the fruit=female option might have a bigger effect on them.
Plant reproduction is a real can of worms. You might get more accurate annotations with something like “flower types seen” and then having male/staminate, female/pistillate, hermaphrodite/perfect and allowing more than one choice to be selected.

That’s an important point.

Hmm, I don’t see an easy way to fix this. If the system knew which taxa were dioecious, it could determine if an observation were female or male automatically.

The “Cannot be Determined” option is being used for multiple purposes: (1) there is no evidence of flowering; (2) there is evidence of flowering but no flowers or fruit are present; (3) there are flowers present but the flower parts are not visible; and lastly, (4) the annoation has been reviewed. So the data provided by the option are ambiguous and therefore not very useful.

The current sex annotation has the same issue as the flowers/fruit annotation, that is, there is no way to mark the annotation as “annotation reviewed”. Without that, one keeps visiting the same observation again and again.

With minor modifications, the new annotation could be used to investigate these questions.

This is precisely the proposal in this thread.

It’s difficult to know – the current sex option isn’t really suitable for monoecious plants with separate male and female flowers. So people can’t use it effectively for research questions about male/female blooming phases of such plants.

While the proposed annotations for floral sexual organs would not capture female plants that are fruiting, I imagine it would be easy enough to combine this with results for observations with the phenology annotation “fruit or seeds”; it would just be a two-step process rather than a single query.

Monoecious for plants means separate male flowers and female flowers on the same plant.

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All of these mean the exact same thing regarding the data though. It has been reviewed and the other options cannot be chosen based on the evidence provided. It doesn’t really matter why. Maybe better wording would be “Necessary evidence not supplied or is unclear” but I think “Cannot be Determined” is fine. Whatever the wording, it is a very important option.

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