mmcavall wrote: ↑Wed Aug 17, 2022 11:50 am
The ADBLPs list reports self sterility/fertility but most of the self-sterile are monoicious species and will always have male and female parts in the same individual. As far as I know, dioicy is the exception and is not common in cacti. Maybe only a few examples can be cited? Or am I wrong?
The list also reports male/female sterility when observed. For example, the listing for G. buenekeri reports that both female and male sterility have been observed ("fs/ms"). Looking at the other gymnos in that section, dioecy seems to be a feature of subgenus Macrosemineum?
I did find the following:
Dicliny occurs when some members of a population
normally produce flowers that are unisexual instead of her-
maphroditic and has been reported in several Cactaceae
taxa. Dioecy (co-occurrence of androecious and gynoe-
cious plants) occurs in Echinocereus coccineus (Hoffmann
1992) and Opuntia stenopetala (Parfitt 1985). Gynodioecy
(consisting of hermaphroditic and gynoecious plants) has
been reported in Mammillaria dioica (Ganders and
Kennedy 1978; Parfitt 1985) and M. neopalmeri (Parfitt
1985). Trioecy (co-occurrence of androecious, gynoecious,
and hermaphroditic plants) occurs in P. pringlei (Fleming
et al. 1994) and Selenicereus innesii (Innes and Glass 1991).
Hermaphroditic, dioecious, and trioecious populations
have been documented for Opuntia robusta (Parfitt 1985;
del Castillo 1986; Hoffmann 1992).
I also found this paper on dioecy in Echinocereus: https://www.journals.uchicago.edu/doi/f ... 086/697072
But just searching the ADBLPS list, you'll get 34 hits for "fs/ms" (more if you search "ms" or fs" alone), so it's likely there are more dioecious species that haven't been scientifically documented.
DaveW wrote: ↑Wed Aug 17, 2022 2:10 pm
Also what should be remembered whilst some are male or female flowers they may look to have both stigmas and anthers present but they may be atrophied and non functional so you may have to look hard to see if they have viable pollen on the anthers. The same applies to whether the stigma lobes are functional.
Good point, Dave. I have noticed on my plants that some flowers had their stigma lobes fused or that the anthers don't release visible pollen grains when brushed or rubbed with a finger. I thought maybe it was health or genetic defect issue, but now I wonder otherwise.