Indica~100% Indica18-19% THC

Purest Indica

Also known as: The Steve Murphy Afghan, Steve Murphy's Afghan, Purest Indica IBL, Northern Lights #1, Hash Plant

Breeder: Authentic Genetics (Todd McCormick)

Purest Indica is a pure Afghan/Hindu Kush landrace inbred line — the "Steve Murphy Afghan" — that is the foundational parent of the entire Northern Lights family and, through it, a vast portion of modern indica-dominant hybrids. Selected and named by Steve Murphy in 1970s Seattle, inbred by "Seattle Greg," and reproduced after ~40 years by Todd McCormick's Authentic Genetics, it is prized as high-resin, gas-heavy hash-plant parent stock. It offers a heavy, sedative narcotic body high, an acrid burnt-rubber/skunk funk, a short leafy Christmas-tree structure, and a fast finish — the exact traits it lends as the father in Prime Cuts' GDP x Purest Indica project. It is sold today as regular (non-feminized) seed, so expect a natural male/female split, and while it is verified as a real named cultivar via Authentic Genetics and SeedFinder, the breeder does not publish strain-specific yield or height figures.

Lineage

Afghan / Hindu Kush landrace IBL

THC Range

~18-19%

Flower Time

7-10 weeks

Difficulty

Intermediate

Lineage & Genetics

Cross: Afghan / Hindu Kush landrace IBL

Purest Indica's value is as a pollen donor and structural-and-finish parent. As a male it breeds consistently, contributing body, density, and finish time without overpowering the mother, and is prized as high-resin, gas-heavy parent stock. In the Prime Cuts GDP cross specifically, it blends its own earthy, acrid Afghan funk with Granddaddy Purple's sweet, fruity grape terpenes to produce deep purple potential and heavy resin content, and it pulls finish time toward the fast end. Historically it contributed exactly these traits — resin, fast finish, indica sedation, short stature — to Northern Lights #1, #2, and #5. Note that the purple in "GDP x Purest Indica" comes from the Granddaddy Purple mother, not from Purest Indica, which is not documented as a purple line.

Lineage Dispute

"Purest Indica" is not a generic landrace label but a specifically named, documented Afghan inbred line (IBL) — the "Steve Murphy Afghan," selected and named by Seattle grower/author Steve Murphy (pen name Murphy Stevens), inbred and preserved by "Seattle Greg" (Greg McAllister), and today reproduced and sold as regular seed by Todd McCormick's Authentic Genetics / AG Seed Co. Two areas require care. First, naming confusion: multiple similarly-named products exist and must not be conflated (e.g. Sensi Seeds' "Pure Indica" is a separate product; seed-cloud.com even lists the breeder as "Seattle Greg" for a "Purest Indica" — same lineage story, different vendor framing). Because the Prime Cuts cross GDP x Purest Indica is itself an AG Seed Co release, the AG Seed Co / Steve Murphy Afghan attribution is the correct one. Second, the broader Northern Lights numbering history is genuinely disputed — the ICmag record contains competing first-person accounts and skeptics who challenge McCormick's/NLSG's provenance claims — so the finer points of who made which numbered NL cross should not be stated as settled fact. The well-supported claims are that Purest Indica is a pure Afghan IBL and the ancestral base of the Northern Lights line. A minor date discrepancy also exists: Cannapedia dates Murphy's book to 1973 while better sources say 1975 (prefer 1975).

Terpene Profile

DOMINANT

Myrcene — Cannapedia lists Myrcene as the dominant terpene, consistent with the strain's earthy/hash/skunk nose. Exact percentages are not lab-confirmed for this line.

SECONDARY

Caryophyllene — Listed alongside Myrcene as a dominant/secondary terpene by Cannapedia; contributes the spicy, gassy edge of the profile.

SECONDARY

Limonene — Implied by Todd McCormick's SC Labs testing, which found at least one phenotype with an almost identical terpene profile to OG Kush (a gassy-earthy myrcene/caryophyllene/limonene/humulene-type blend).

Aroma: Acrid, skunky, and gassy, with distinct burnt-rubber and earthy/dank notes. Growers describe it as "dank and gassy, somewhere between burnt rubber with a hint of acrid smelling skunk"; the breeder lists burnt rubber, skunk, and acrid earth. The line "makes thiols" (sulfur volatiles), the biochemical basis for its skunky character — it could easily be called skunk if named by description. It is intense and pungent but simple and one-dimensional rather than fruity or layered; High Times noted the inbred line was extremely resinous but "lacked complex flavor," which is why the crew crossed it to add flavor and vigor.

Flavor: A heavy, old-school Afghan "funk" — acrid skunk, burnt rubber, diesel/gas, damp earth, and hash, with little sweetness on its own. Cannapedia flavor descriptors include ammonia, earthy, hash, pungent, and skunk. Some phenotypes veer toward an OG-Kush-like gassy/earthy character per McCormick's terpene testing. (Any sweet berry/grape notes in the Prime Cuts GDP cross come from the GDP mother, not this parent.)

Effects & Experience

Onset: Fast-arriving physical heaviness centered in the body and limbs, with minimal racy head effect given its pure-indica Afghan makeup (general indica pattern consistent with the sources).

A heavy, sedative, narcotic body high — Cannapedia's aggregated profile is Relaxed (~90%), Sleepy (~85%), Body High (~80%), Euphoric (~60%) — progressing to couch-lock and drowsiness. Seattle Greg reportedly kept the pure Afghan for its sedative effects. Best suited to evening/nighttime use.

Duration: Not precisely documented; typical for a potent indica (roughly a couple of hours of peak with a longer tail) — stated as inference.

Commonly Reported Uses

Insomnia / sleepChronic painStress reliefAppetite stimulation

Grower's Notes

Flower

7-10 weeks

Indoor Yield

~400-550 g/m² (Afghan/HK landrace benchmark;

Outdoor Yield

~500-600 g/plant (landrace benchmark);

Difficulty

Intermediate

Height / Stretch

Short/compact broadleaf (~100 cm indoors)

Environment

Indoor/greenhouse/outdoor; warm, dry, low

Purest Indica is the heirloom "Steve Murphy Afghan" hash-plant inbred line that seeded the entire Northern Lights family, and it grows exactly like the pure Afghan it is: hardy, resin-drenched, and beginner-friendly, with one firm rule, which is low flowering humidity. Because it is sold only as regular seed, plan on sexing plants, and expect a leafy, sticky, high-resin crop. Broader figures below are Afghan and Hindu Kush landrace benchmarks used only for calibration.

Growth Structure and Training

This is a short, stocky, dense broadleaf plant with a distinct Christmas-tree shape and long, draping leaflets over tight internodes. It is very leafy, so expect more trim work than a modern hybrid. Give it adequate veg time and use topping to maximize yield, and because it stays short and bushy it is a natural SOG candidate. It is sold only as regular seed and is never feminized, so the male is specifically valued for breeding, as in the Prime Cuts GDP cross.

Flowering Time and Harvest

The breeder and SeedFinder list seven to ten weeks, roughly 63 days, so a tight eight to nine weeks is the best central estimate for the finished female. Harvest on trichome maturity, and outdoors the category finishes late September to early October in the Northern Hemisphere, ahead of the autumn rains.

Yield

Buds are described as incredibly leafy, sticky, and huge, and the line is called high-yielding and vigorous. As calibration only, Afghan and Hindu Kush benchmarks run about 400 to 550 grams per square meter indoors and 500 to 600 or more grams per plant outdoors. Yield rewards veg time and training.

Nutrient Management

No strain-specific feeding data exists, so treat it as a moderate feeder. Afghan landraces are hardy and tolerant of nutrient fluctuation, so standard indica calcium-magnesium and pH ranges apply, near 6.2 to 6.8 in soil and 5.5 to 6.2 in hydro. Taper nitrogen and push phosphorus and potassium in bloom.

Environment and Climate

The single most-cited requirement is low humidity, since the plants prefer dry air and look like they came out of an Afghan desert. Keep flowering relative humidity around 40 to 50 percent to avoid bud rot in the dense colas, and run strong airflow above and below the canopy. It does well indoor, outdoor, and greenhouse in warm, arid-to-Mediterranean conditions, and a late-flower night-temperature drop can push resin and coloration.

Pest and Disease Resistance

The line has natural resistance to pests, disease, and mold as a hardy Afghan landrace, but the buds are dense, so in damp air those tight colas remain a botrytis risk. Manage humidity and airflow, and lollipop the lower third to eliminate dead-air zones.

Bud Structure and Trichomes

Expect dense, sticky, resin-heavy buds, the quintessential hash-plant phenotype with heavy trichome coverage. Resin and stickiness are the single most emphasized trait of this line, historically called a state-of-the-art indoor indica with unrivaled resin content.

Color Development

No source describes Purest Indica itself as a purple line; its documented look is classic frosty green Afghan with heavy silver-white trichome frost. Any purple in the Prime Cuts GDP x Purest Indica cross comes from the Granddaddy Purple mother, not this line.

Drying and Curing

Use a standard slow dry at about 60 degrees Fahrenheit and 55 to 60 percent relative humidity over seven to fourteen days until small stems snap, then jar-cure with daily burping over several weeks to preserve the pungent thiol and terpene character.

Wash and Extraction

This is explicitly a hash plant and high-resin parent stock, a natural candidate for bubble hash, dry sift, and rosin. Traditional dry sift over 72 to 120 micron screens grades the resin, while ice-water hash at 0 to 4 degrees Celsius is standard, and quality Afghan flower commonly returns three to six percent ice-water yield with dry sift around 10 to 15 percent of trim and smalls. Work cold to protect the trichome heads.

History & Origin

In mid-1970s Seattle, author Steve Murphy (pen name Murphy Stevens) cultivated a short, broad-leaf Afghani he called "Purest Indica," reportedly acquired via Hippie-Trail travelers; he published "How to Grow Marijuana Indoors Under Lights" (1975; later 1977, 1979) and opened the Indoor Sun Shoppe. Around 1979 Greg McAllister ("Seattle Greg") was gifted four Purest Indica seeds, inbred them, and shared seed whose out-crosses returned and were numbered #1-#11 — the Northern Lights family (#1 closest to Purest Indica, #11 most tropical). In the early 1980s NL#2 (Purest Indica x Afghan) and NL#5 (Purest Indica x a Hawaiian sativa) emerged as standouts. In 1984-1985 Seattle Greg sent Northern Lights material to Nevil Schoenmakers / The Seed Bank in Amsterdam but deliberately withheld Purest Indica itself so Holland could not reproduce the hybrids without him, which is why the line stayed rare. NL#5 x Haze went on to win multiple High Times Cannabis Cups (1989, 1990, 1992) — awards that belong to the NL descendants, not to Purest Indica. After the 1989 Operation Green Merchant raids, the original US lines were largely lost. A cache of the original seeds sat in a Seattle family freezer until it was discovered in 2019, and in 2020 Seattle Greg gave the recovered stock to Todd McCormick, who reproduced it — the first reproduction in ~40 years — now sold via Authentic Genetics. Its cultural impact is enormous but indirect: it is the ancestral Afghan base of Northern Lights, one of the three pillars of modern cannabis breeding alongside Skunk #1 and Haze.

Notable Crosses

Strains bred using Purest Indica as a parent:

Northern Lights #1— Essentially the inbred Purest Indica

Northern Lights #2— Purest Indica x (Afghan x Afghan)

Northern Lights #5— Purest Indica (Afghan) x Hawaiian sativa→GDP x Purest Indica— Granddaddy Purple x Purest Indica→

OG Kush x Purest Indica— OG Kush x Purest Indica

Skywalker OG x Purest Indica— Skywalker OG x Purest Indica

Sour Diesel x Purest Indica— Sour Diesel x Purest Indica

Tahoe OG x Purest Indica— Tahoe OG x Purest Indica

LA Kush Cake x Purest Indica— LA Kush Cake x Purest Indica

True Triangle x Purest Indica— True Triangle x Purest Indica

Hawaiian Lights— Purest Indica x NL#5

Violaceous II— Lavender Kush x Purest Indica

Frequently Asked Questions

5 common questions about Purest Indica

What is Purest Indica and what are its genetics?

Purest Indica is a indica cannabis strain (~100% Indica) bred by Authentic Genetics (Todd McCormick). It is a cross of Afghan / Hindu Kush landrace IBL, testing at ~18-19% THC. Purest Indica is a pure Afghan/Hindu Kush landrace inbred line — the "Steve Murphy Afghan" — that is the foundational parent of the entire Northern Lights family and, through it, a vast portion of modern indica-dominant hybrids. Selected and named by Steve Murphy in 1970s Seattle, inbred by "Seattle Greg," and reproduced after ~40 years by Todd McCormick's Authentic Genetics, it is prized as high-resin, gas-heavy hash-plant parent stock.

What does Purest Indica smell and taste like?

Purest Indica's dominant terpenes are Myrcene. The aroma is described as acrid, skunky, and gassy, with distinct burnt-rubber and earthy/dank notes. growers describe it as "dank and gassy, somewhere between burnt rubber with a hint of acrid smelling skunk"; the breeder lists burnt rubber, skunk, and acrid earth. the line "makes thiols" (sulfur volatiles), the biochemical basis for its skunky character — it could easily be called skunk if named by description. it is intense and pungent but simple and one-dimensional rather than fruity or layered; high times noted the inbred line was extremely resinous but "lacked complex flavor," which is why the crew crossed it to add flavor and vigor.. The flavor profile features a heavy, old-school afghan "funk" — acrid skunk, burnt rubber, diesel/gas, damp earth, and hash, with little sweetness on its own. cannapedia flavor descriptors include ammonia, earthy, hash, pungent, and skunk. some phenotypes veer toward an og-kush-like gassy/earthy character per mccormick's terpene testing. (any sweet berry/grape notes in the prime cuts gdp cross come from the gdp mother, not this parent.).

What are the effects of Purest Indica?

Fast-arriving physical heaviness centered in the body and limbs, with minimal racy head effect given its pure-indica Afghan makeup (general indica pattern consistent with the sources). A heavy, sedative, narcotic body high — Cannapedia's aggregated profile is Relaxed (~90%), Sleepy (~85%), Body High (~80%), Euphoric (~60%) — progressing to couch-lock and drowsiness. Seattle Greg reportedly kept the pure Afghan for its sedative effects. Duration is typically not precisely documented; typical for a potent indica (roughly a couple of hours of peak with a longer tail) — stated as inference.. Commonly reported uses include Insomnia / sleep, Chronic pain, Stress relief, Appetite stimulation.

How hard is Purest Indica to grow?

Purest Indica is rated intermediate difficulty. It flowers in 7-10 weeks, reaches short/compact broadleaf (~100 cm indoors) in height, and yields ~400-550 g/m² (afghan/hk landrace benchmark; not breeder-published) indoors. Best suited for indoor/greenhouse/outdoor; warm, dry, low humidity (40-50% rh flower) environments.

What strains were bred from Purest Indica?

Purest Indica has been used as a parent in several notable crosses, including Northern Lights #1, Northern Lights #2, Northern Lights #5, GDP x Purest Indica, OG Kush x Purest Indica. Its genetics contribute to a wide range of modern cultivars.

Sources & References (32)

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