I downloaded it. No etymology is given, but they have given a picture of the fruit. I think I can guess its etymology. The name can be split into two: sperma+coca. The sperma stands for sperms. Coca is similar to the coco in coconut. Its etymology is given as related to the appearance of a face (coconut or kera, the name after which Kerala, land of coconut, my own place in India) got its name from.But I think coco is related to sexuality; koka zastra is Sanskrit (and Malayalam) too meaning science of sex. Now spermacocae can mean sperm-sex, and the hairy bilobed fruit of spermacocae remota looks like the hair covered sexual organ testis, the repository of sperms. The plant is common to India and Kerala too. ThaaRaavu, the name for ducks, in Malayalam, can also be taken as 'becoming thaaR', and thaRu is the name of the undergarment worn when children attain sexual maturity. The coconut is also hairy, but not bilobed.
It all means that when naming plants and animals ancient people definitely noted similarities with human body parts.
The website Florabase of the Western Australia Herbarium says: "from the Greek sperma for "seed" and "point"; said to refer to the capsule being surrounded by the calyx points." Can't confirm.