Often Carica papaya will pop up in my garden, usually in the most awkward locations, because birds (I assume) drop seed, though because they pop up pretty often, I do not make an Observation every time they do. Here some are, though!
Anyway, the sex of these trees are easily determined by their flowers (and which ones fruit). Some have strictly male blooms, some have strictly female blooms, and I understand that some may have both male and female blooms though I have not observed one like this in my garden. (The Annotations for Sex do not seem to allow for this third option.)
What I have observed is that sometimes a tree will change from strictly male to strictly female blooms (or strictly female to strictly male blooms), which I understand happens with this species. I am not sure how or if to Annotate this either.)
My question: is this sex reversal unique to papayas or are there other plants that do this?
Thank you for these links, which are chock full so I am taking my time to read them.
The second one led me to Simultaneous hermaphroditism and the article there said, “Most plants are simultaneous hermaphrodites with it occurring in 80% of angiosperms.”
This made me wonder if the remaining twenty percent, papaya included, are the sequential kind?
The section in Terminology in the first link seems to contain a multitude of terms that refer back to each other. This made me concerned that I may have used words that are out of date and/or otherwise may have been hurtful to iNat Community Members (or lurkers), albeit very much unintentionally, perhaps even in the title of this post, and if this is the case, I apologize profusely.
What are the best terms from this list to avoid causing harm but convey what I mean?
My understanding is that protandry refers to plants which bear bisexual / hermaprophditic flowers which individually (within the same flower) have the male parts developing and do their thing before the female parts develop and do their thing.
From what I’ve read in the last few minutes about papaya, it sounds like they are (possibly) trioecious – that is, individual plants can bear only unisexual male flowers, only unisexual female flowers, or only bisexual flowers (both male and female parts in the same flower; the bisexual flowers may or may not be protandrous, I couldn’t find anything on that). It sounds like the sex reversal process is when a particular plant changes from one of those three to one of the other three – e.g. a plant bearing bisexual flowers transitions to bearing only unisexual flowers, or vice versa; or a plant bearing only unisexual male flowers transitions to bearing only unisexual female flowers, or vice versa. It would seem that the genes of the plant don’t change though, it’s just how the plant expresses its sex that changes.
I think? Maybe @sedgequeen or @jdmore can check me on any inaccuracies or mistruths in the above?
Just looking at the first page or two, it sounds like it’s been observed in various other “crop” plants like hemp, corn, and hops. I wonder whether that’s a result of those plants merely getting greater attention, or if there’s a correlation between cultivation and sex reversal.
While I don’t claim to be up-to-speed on the intersection of plant morphology terminology and the latest societo-cultural sensibilities, my impression is that, generally speaking, none of the terms on that page are considered any less appropriate than another (at least not for cultural reasons) – assuming of course that you’re using those terms correctly and that you’re using them to refer to plants, and not to, say, people.
I’d also note that that list and its definitions aren’t necessarily exhaustive. For example, in Cyperaceae, the term “androgynous” has a meaning more specific than just “bisexual” – rather, it refers to bisexual inflorescences in which the male flowers occur near the tip of each spike and the female flowers occur below that. And “gynecandrous” (not on the list) is the opposite – bisexual inflorescences in which the female flowers occur near the tip of each spike and the male flowers occur below that.
Note that androgynous and gynecandrous are terms for sedges that are monoecious – that have separate male and female flowers. Both terms describe the arrangments of those flowers in the spike.
In plants, sex determination can be genetic. It’s thought to be genetic in most dioecious plants (ones with males and females on separate plants). It’s also genetic in some male-sterile corn varieties.
Protandry often refers to development of stamens before pistils within a single bisexual/hermaphroditic/perfect flower (e.g. in Lomatium, a large North American genus in Apiaceae). However, it can also be used to refer to development of male flowers before female ones in a monoecious plant, e.g. the Carex rossii group of sedges.
Some plants have bisexual flowers early in the season and male later (gynomonoecious). There are lots of other variations. In fact, there are lots of different patterns of sex expression just within the grass genus Poa, bluegrasses.