I don't know if you'll want to plant any of these but here are some suggestions:
Asclepias physocarpa-Family Jewels Milkweed
Solanum mamosum-Nipple Fruit
Eriophorum vaginatum-Tussock Cottongrass
Bulbophyllum vaginatum orchid
Hymenosporum flavum-Native Frangipani
Hymenocallis-Spider Lily
Phallus impudicus
Lady-of-the-Night-Brunfelsia americana
Hymenoclea-Winged Ragweed

Good list Trini! lol We also call Asclepias physocarpa Hairy Balls.

:) Karen, I've heard that name too but I can't say it because it makes me blush. :)

Trini, aside from the name of Hymenosporum now that I see it included in such a list, I wouldn't have associated this tree with the others. I have this growing in my own garden, and if I've gotten a proper latin translation for this, hymeno signifies wedding, sporum signifies sport(?), and flavum means yellow. So does it still fit in your opinion? I don't see much that actually could look "naughty" about this plant myself, either in the flowers or the seed pods, but maybe I haven't looked closely enough? Anyone know more about etyomology of latin botanical naming to enlighten me?

Bahia, this is what I found about it:

"Derivation of
Name: Hymenosporum...from Greek, hymen, a membrane and spora, a seed, referring to the winged seeds
flavum.... from Latin, flavus, yellow, referring to the typical flower color"

I hadn't given any thought to the origin. I just think it sounds naughty so I threw it in there. :)

Don't forget peter peppers!

Cool idea, reminded me of a few pix i came across.

You're going to need a Padanus Palm. See Google Images linked below.

Here is a link that might be useful: Google Images - Padanus Palm

I've found that the red peter peppers produce a higher number of peppers that look, um, appropriate, to your garden than the yellow ones, FYI!

Here is a link that might be useful: red peter peppers I grew

I came across another one for the naughty list:
Ceropegia ampliata aka Bushman's pipe, Horny Wonder, Condom Plant.

Here is a link that might be useful: Ceropegia ampliata

LOL at the vine on the tree pic.

Here's a few more plants with suggestive names.

Virgin's Bower - Clematis virginiana
"Cuisse de Nymphe" Rose, AKA "Maiden's Blush" (The French name translates to "Nymph's Thigh")
Hosta "Striptease"
Coleus varieties "Burlesque", "Fishnet Stockings", and "Private Dancer"

"Pink Peculiar" Cuphea ignea looks naughty to me, but to you it may look completely innocent. Naughty is in the mind of the beholder.

Reviving this thread as I too am looking to plant a garden with plants that have dirty names. Here is the hosta list I came up with so far:

Striptease (also Kiwi full Monty which is the same plant)

Little polka dot bikini

Mini skirt

Ecstasy

Seducer

Afterglow

Geisha

Hanky panky

Marilyn Monroe

Satisfaction

Secret love

Get nekkid

Erotica

Double d cup

That's all I have been able to find. Any I am missing that have sexually suggestive names?

Also I would love to have any more ideas for non-hostas than what is listed above. Sun or shade plants would be fine. I have one I found today: Actea 'black negligee'.

Any other recommends?

probably too big for your garden, but "avocado" comes from a Latin American native name for testicals, probably due to the fact that they grow in pairs.

And watch out for pandanus! They don't grow like trees on their own, they become HUGE sprawling clumps of spiky leaves. Spent hours the other day fighting it back from my drivway. You have to prune regularly to get a tree. Oh, but you're only summer growing, that won't be a problem.

Orchids- many. Barrel Cacti in pairs- female. In pairs with a columnar cacti in the middle?..male. Try that and it wont be subtle or need you to explain..lol.

Had to chuckle at the mention of Phallus impudicus. While the fruiting body of this mushroom does fit the idea here, this is of course a mushroom and not something you "plant".