For a fee of flowers
The book Black Orchids is not a novel, but two novellas: "Black Orchids" and "Cordially Invited to Meet Death". These are separate mysteries with separate casts of characters, linked only by the protagonists — Rex Stout's famously eccentric detective, Nero Wolfe, and his right-hand man Archie Goodwin — and the fact that a rare orchid variant appears in both.
[Archie Goodwin:] "... Have you ever been to a flower show?"
Wolfe closed his eyes and sighed.
"Anyway," I went on, "you've seen pictures of the exhibits, so you know that the millionaires and big firms do things up brown. Like Japanese gardens and rock gardens and roses in Picardy. This year Rucker and Dill, the big seed and nursery company, have stolen the show. They've got a woodland glade. Bushes and dead leaves and green stuff and a lot of little flowers and junk, and some trees with white flowers, and a little brook with a pool and rocks; and it's inhabited. There's a man and a girl having a picnic. They're there all day ... They pick flowers. They eat a picnic lunch. ... At four o'clock the man lies down and covers his face with a newspaper and takes a nap, and the girl takes off her shows and stockings and dabbles her feet in the pool. That's when they crowd the ropes. Her face and figure are plenty good enough, but her legs are absolutely artistic. Naturally she has to be careful not to get her skirt wet, and the stream comes tumbling from the rocks into the pool. Speaking as a painter —"
Wolfe snorted. "Pah! You couldn't paint a —"
"Black Orchids" opens at a New York flower show at which the eponymous flowers are on display. Wolfe, a fanatical orchid grower, covets the plants, but other passions are at work as well; what seems at first glance to be an indoor Eden proves to be a hothouse of lust, jealousy, blackmail and no-holds-barred commercial backstabbing. When the horticultural hullabaloo culminates in murder, Wolfe sees an opportunity bring a killer to justice and acquire the orchids at the same time.
The black orchids of the title also appear in "Cordially Invited to Meet Death", the second of two stories in the Nero Wolfe double, Black Orchids; but are not significant for its plot.
The two novellas have one other element in common besides the protagonists and the orchid motif. In both cases, the methods used for committing the murders are original and very cleverly plotted.