June Lockhart played mum in Lassie, Lost In Space

June Lockhart, the soft-spoken actress who exuded earnest maternal wisdom and wistful contentment in two very different mid-20th-century television roles in the heartwarming children's series Lassie (1954 to 1974) and the futuristic Lost In Space (1965 to 1968) - died on Oct 23 at her home in Santa Monica, California. She was 100.

- Anita Gates

Her death was announced by spokesperson Harlan Boll.

Lockhart replaced Cloris Leachman in the role of Ruth Martin, a farm wife and the foster mother of Jon Provost’s character and his courageous collie Lassie, in 1958, at the beginning of the show’s fifth season.

After six years of dispensing homespun wisdom, Lockhart was herself replaced, along with her human costars, in favour of a forest ranger who would guide the show’s canine heroine through her further adventures.

In 1965, Lockhart returned to television, playing a wife, mother and interplanetary explorer turned castaway in Lost In Space.

Her TV family included a robot that seemed to announce “Danger, Will Robinson”, alerting the show’s boy hero to extraterrestrial menace, as often as Lassie’s sensitive ears and nose alerted her to earthly emergencies.

The series, which combined an over-the-top villain with low-budget production values, became something of a camp classic, acquiring a devoted following years after its original run.