The film begins with 21-year-old Toni Simmons trudging across the road at night to post a letter. Subsequently, she returns to her apartment and attempts to gas herself using a "second-hand" stove. Fortunately for her, her neighbor, Igor Sullivan, smells the gas and rescues her from imminent death using rescue breathing, which evolves into a French kiss after Toni regains consciousness.
The movie then moves to the cause of the suicide attempt. Toni's lover Julian, a dentist and philanderer, had previously told Toni that he has a wife and three kids, in order to avoid commitment issues. However, upon learning of the suicide attempt, he decides to rethink his bachelor status and to marry Toni, resulting in him needing a wife to divorce.
In order to resolve his dilemma, Julian decides to ask Miss Stephanie Dickinson, his spinsterish Swedish assistant of ten years, to pose as his wife. At first unwilling, she ultimately accepts the role, since she has secretly developed a crush on Julian. However, upon meeting Miss Dickinson, Toni intuitively senses Miss Dickinson's love for Julian. This causes her to ask Julian to help Miss Dickinson find another man, in order for everyone to be happy. In order to resolve the situation, Julian involves several other characters, including Julian's friend Harvey, Señor Arturo Sánchez, and Igor. Ultimately, Toni finds out about the lie and leaves Julian for Igor, while Julian falls in love with Miss Dickinson.
The namesake of the film is a prickly cactus that Miss Dickinson keeps on her desk at the dentist's office. Similar to Miss Dickinson, the cactus is cold and inhospitable. However, by the end, both the cactus and Miss Dickinson have bloomed.
|Walter Matthau||Dr. Julian Winston||a dentist|
|Ingrid Bergman||Stephanie Dickinson||Dr. Winston's assistant|
|Goldie Hawn||Toni Simmons||Dr. Winston's girlfriend|
|Jack Weston||Harvey Greenfield||a friend and patient of Dr. Winston|
|Rick Lenz||Igor Sullivan||a writer and Toni's neighbor|
|Vito Scotti||Señor Arturo Sánchez||a diplomat and patient of Dr. Winston|
|Irene Hervey||Mrs. Durant||a patient of Dr. Winston|
|Eve Bruce||Georgia||a date of Harvey Greenfield's|
|Irwin Charone||Record Store Manager||Toni's employer|
|Matthew Saks||nephew||one of Mrs. Dickinson's nephews|
In her first major film role, Goldie Hawn, who had earlier been described as the "dizzy cream puff who is constantly blowing her lines [on Laugh-In], was especially commended for being "a natural reactress; her timing is so canny that even her tears run amusingly. In fact, her performance in Cactus Flower led to her only Academy Award win to date.
In addition, there was a nomination for Ingrid Bergman and an additional one for Goldie Hawn: