Lassie - Episode 108 - "The Berrypickers" Season 4, #5 (10/6/1957):

Timmy and Gramps go out to pick huckleberries for pies for the church supper. When Gramps takes a nap, Timmy goes off by himself and accidentally starts to pick and eat nightshade berries which makes him very ill.
TRIVIA - the difference between huckleberries and nightshade are small enough that a young child, like Timmy, would fail to spot the differences. According to medical journals, however, while nightshade has the reputation of being very poisonous, recent studies and findings dispute this claim. The active ingredient in the berry, solanine, can be injurious to small children, but rarely to adults, and the plant has many medicinal purposes. Huckleberries, on the other hand, can be ingested freely with gusto, and the only result will be a berry stained face, and possibly a bit of gastric upset (belly ache) later on.
NOTE: This recording has been edited to remove commercials and to add titles and descriptions. The re-broadcast has not been stretched or modified in any way from the original film which was distributed for TV viewing in classic black and white early 1950's "square TV screen" format. "Lassie" is copyrighted and owned by Classic Media. The first 4 seasons of "Lassie" were later syndicated as "Jeff's Collie". Recorded from COZI TV in 2013 via free over-the-air antenna TV.