genus, genius, ingenius, ingenuous

Genus or genus is a scientific classification, one of the groups into which living organisms are divided--
He can identify all the local flora by family, order, class, genus, and species.
This is of a different genus than the other plants we have been studying.
Genus may be used to means class or group, figuratively--
This is a different genus of business plan.

Genius or genius means a person of uncommon intelligence or understanding--
They insisted he was a genius, but he insisted that he just worked very hard.
As the saying goes, "genius is 1% inspiration and 99% perspiration".
Genius may also mean the spirit or character of a nation or set of people--
Independence of mind is often called the genius of the American people.
Genius is an old-fashioned term for the guardian spirit of a place--
The genius of these woods may not like it if we litter.

Ingenious or ingenious ( one word ) means very clever or original; inventive--
This is an ingenious invention; I don't know how anyone ever thought of it.
His new software is ingenious; it's different from anything else we have seen.

Ingenuous or ingenuous means naive; innocent or ignorant of the ways of the world; artless; with complete candor--
His ingenuous explanation demonstrated that although he was artless, he was intelligent and observant.
She had lived all her life among theater people, and he was sure that her ingenuous manner was insincere.

Now that you know that, you can say--
"Some people consider it ingenious to place a genius in a different genus, apart from the rest of humankind, but this is ingenuous; geniuses just work harder."

Note--"ingenue" or "ingénue" means a person who is artless or naive, most commonly used to refer to a role on the stage or in a film--
That young woman would be just right in the role of the ingenue.
She is getting too old to play the ingénue.
Note # 2--"ingenuity" means cleverness, originality, or inventiveness--
It's just another product of Yankee ingenuity.
Note # 3--"genii" is a plural ( more than one ) form of  "genius", although "geniuses" is preferable, except when "genius" is used to mean the spirit of a place--
The genii of this place supposedly protect it from the incursions of civilization.
"Genii" may also be the plural of "genie", meaning a magical being, as in the tales of the Arabian Nights--
The genii who serve the evil magician have left him; out hero will win the day now.
Note # 4--"genie" means a magical being, like the one in Aladdin's lamp--
If  I rub this lamp, will a genie appear?