「Emerging shafts over female's screwing orifice」can be the male's penis, which any child will tell you resembles some varieties of MUSHROOM. Other varieties of fungi distinctly resemble the darkened labia of female genitalia:「emerging with the female screwing orifice」as MUSHROOMS, a reference also perhaps to the sometimes musty odor associated with both of these referents, particularly after coming in contact with one another.
　Japanese pronunciation describes a「crow melon」emanating from a pure white bloom as the sexual parts (of the vine) open, that matures into a bright red ripened gourd, a vine with tenacious tendrils from which extrication is difficult after it starts to grow on you.「Crow」as an all-black bird or chick (smeared with feces) is a Chinese euphemism for a service provider of anal sex, and「melon」is another euphemism of a vagina, juicy and filled with seeds at the pithy core, particularly upon deflowering and appearing as that opened white bloom covered with ejaculate, which finally ripens into a blood-red pulpy mass.
　Creeping vines do not possess the physical structure to permit standing alone, hence vines creep along soil until an erect tree, wood (木) or woody is located, at which time the parasitic vine begins to wrap itself around the erect wood and climb with screwing, twisting vertical motions using the host for support, until ultimately the vine and tendrils strangle the host wood to death by sapping most of the nutrients and water from the soil and the sunlight from the treetop for itself. These same attributes obviously could apply to a person with pulverized feet bones who has become an anal-oriented service provider, and to a client who has hired such services during a short-term rental but subsequently become hopelessly enamored.
　Elements utilizing「emerging with one's mother-in-law」likely need no explanation.

Modern definitions (that generally disregard history) …excluding politically incorrect concepts and other meanings deemed offensive today; may list only pigeonholed definitions, euphemisms, or meaningless mnemonics)
Chinese: mushroom
Unihan extended: mushrooms
EDRDG: mushrooms