Is Lamb’s Bread indica or sativa? Its genetics and family tree

No named parents

Leafly describes Lamb’s Bread as “a sativa marijuana strain of unknown genetic origin” whose original breeder is unknown, and its family tree shows one parent: Jamaican, Leafly’s entry for the island’s indigenous landraces, which “tend to be sativa in structure and effect” because of Jamaica’s latitude and climate.^1,2 Leafly’s guide to landrace strains lists Lamb’s Bread as “a landrace from the island of Jamaica”.⁸

Others are less sure. Verilife, a dispensary chain, writes that “we’re not exactly sure where it comes from”; Zamnesia, which sells seeds under the name, calls the lineage and origin “a part of its mystique”; SeedFinder files the original under “Unknown or Legendary”.^9,10,11

How sativa is it?

Every database labels it a sativa: Leafly files it under sativa, AllBud gives a 5:95 indica/sativa ratio, Wikileaf calls it “almost entirely Sativa”, and Weedmaps a sativa-dominant hybrid.^1,14,18,19 Seed sellers say the same: Crop King’s feminized line is “95% Sativa”, Zamnesia’s a pure sativa, Blimburn’s “mostly Sativa”.^10,12,20 Leafly’s grow notes add a wrinkle: four phenotypes, three sativa-leaning and a fourth with “more indica-like characteristics”.¹

The only genetic evidence points elsewhere. In the first large genetic study of cannabis strains (81 marijuana and 43 hemp samples), Sawler and colleagues reported that “Jamaican Lambs Bread (100% reported C. sativa) was nearly identical (IBS = 0.98) to a reported 100% C. indica strain from Afghanistan”, and concluded that “the genetic identity of a marijuana strain cannot be reliably inferred by its name or by its reported ancestry”.^3,21 Wikipedia summarizes the same finding as a Lamb’s Bread “claimed to be 100% Sativa” that “was in fact almost 100% indica”.²² That was one sample bought under the name; it shows the label is unreliable, not that every Lamb’s Bread is an Afghan indica.

Bread or Breath?

Leafly treats Lamb’s Breath as an alias of Lamb’s Bread; Weedmaps does the reverse, filing the strain as Lamb’s Breath with Lamb’s Bread, Lambsbread, Lambs Breath and Lamb Breath as aliases; AllBud writes “Lamb’s Breathe”.^1,18,19 Our lab matching accepts five normalized spellings (lambs bread, lambsbread, lambs breath, lamb bread, lamb breath), with or without the apostrophe, and treats them as one name.²³

Explanations of the name differ and none is documented. James Riddle of Lamb’s Breath Seeds, who once treated the names as synonyms, now quotes Steve Lamb’s memoir: “The farmers I worked with began calling our new strain Lamb’s Bread, because some of the buds were as large as loaves of bread.”¹⁵ A Leaf Magazine feature on a seed company’s autoflower says the Bread spelling is a “misinterpretation of the Jamaican Patois pronunciation” of Breath.²⁴ Yardie Seeds says there is controversy over “if it’s lambsbreath or lambsbread or if they are 2 different things” and that “no one really knows”.²⁵ Wikipedia’s list of Rastafari names for cannabis (callie, Iley, the herb, the holy herb) does not include lamb’s bread.²⁶

The seed lines sold under the name

SeedFinder lists six breeders’ versions of Lambs Bread and says the legendary original “is/was never available as feminized seeds”; what is sold today is mostly feminized seed.^11,27 Zamnesia, Blimburn and Yardie Seeds sell feminized lines they describe as Jamaican sativa; Legendary Hybrids offers feminized seed of a clone it has kept for more than ten years and calls “The Bread”; Crop King Seeds sells a 95% sativa feminized line and an autoflower that crosses “Jamaican Sativa x Ruderalis”.^{10,12,17,20,25,28}

One line has a dated collection story. James Riddle says he bought seeds from a grower in the hills above Negril, Jamaica, in 2018, grew them in Minnesota and then as an isolated seed crop in Vermont after moving to New England in 2020, and his Irie Select is “6th generation line-bred” regular seed from that stock.^29,30 That account documents his stock, not every plant sold under the name.

What our lab data adds

Strict name matching found 117 flower tests of Lamb’s Bread under its accepted spellings and excluded 174 results sold under near-miss names, 90 of them flower.²³ Almost all of the excluded results, 161, carried one name, “19 LAMBSBREAD (CBD)”: a CBD product line, not the THC flower this guide describes.²³ Another 11 were sold as “Leeroy’s Lambsbread” in four pack sizes.²³ Leafly lists Blueberry Lambsbread, a Blueberry × Jamaican Lamb’s Bread hybrid, as a separate strain.⁶