Green’s Dictionary of Slang

1. high-grade marijuana, esp. that imported from South or Central America.

1944		Marihuana Problem in City of N.Y. in Johnson Indian Hemp (1952) 35: The ‘panatella’ cigarette [...] is considered to be more potent than the ‘sass-fras’.
1956		Billie Holiday Lady Sings the Blues (1975) 44: Jimmy’s got the best panatella you ever smoked in your life.
1989		(con. 1930s) Courtwright & Des Jarlais Addicts Who Survived 85: I got acquainted with him in 1931 [...] three for a half. I’d been smoking other types of marijuana, what they called ‘panatelles.’ But this here to me was the best I ever had.

2. a large marijuana cigarette, resembling a thin cigar.

1946		Mezzrow & Wolfe Really the Blues 229: They rolled it in a different sized paper, about an inch and a half longer than mine and much thinner, and they called their product a ‘panatella’.
1969		R.R. Lingeman Drugs from A to Z (1970) 201: panatella Bigger, fatter, more potent marijuana cigarette made of Central or South American marijuana.
1980		‘Gloss. of Drug Terms’ National Instit. Drug Abuse.
2001		ONDCP Street Terms 16: Panatella — Large marijuana cigarette.