Palmarosa

Palmarosa is a tropical grass that smells of roses, which is as odd as it sounds. The group also covers lemongrass and gingergrass, all Cymbopogon species, all smelling nothing like each other. What sets palmarosa apart is geraniol, at three quarters to nine tenths of the oil, one of the highest of any oil sold. At a tenth of a percent, palmarosa oil completely stopped brewer's yeast growing by wrecking its cell membrane.^[1] It also held back Fusarium and Aspergillus moulds.^[2]

Lemongrass

Cymbopogon citratus

Also Known As: West Indian Lemongrass
Family: Herbal
Perfumery Note: Top
Intensity: Strong
Extraction: Steam Distillation
Plant Parts: Leaves
Origins: India, Sri Lanka, Guatemala
Effect: Focus & Mental Clarity, Respiratory Support, Energy & Uplifting
Aroma: Citrus, Herbal, Sharp
Applications: Diffusing & Inhalation, Skincare, Massage & Body, Perfumery & Fragrance Making, Household & Cleaning
Price: $$$$A fast-growing tropical grass that can be harvested multiple times per year with a high yield

Lemongrass is the sharp one, more lemon than lemon itself. Two thirds to four fifths of the oil is citral, the compound that carries that smell. It is the best studied of the tropical grass oils. In lab tests it and citral held back fungi and bacteria, including the ones behind athlete's foot and food poisoning.^[3]^[4] Citral is also a known skin sensitiser, so this is one to dilute properly.^[5]

Rosha Grass

Cymbopogon martinii

Also Known As: Palmarosa, Indian Geranium
Family: Herbal
Perfumery Note: Middle
Intensity: Medium
Extraction: Steam Distillation
Plant Parts: Grass, Leaves
Origins: India, Nepal, Madagascar
Effect: Grounding & Centering, Energy & Uplifting
Aroma: Floral, Sweet, Rose-like
Applications: Diffusing & Inhalation, Skincare, Massage & Body, Haircare, Perfumery & Fragrance Making
Price: $$$$A fast-growing grass with a high yield, similar to lemongrass but with a rosy scent

Rosha grass is palmarosa under its Indian name, the same grass and the same oil. The name shows up on oils traded out of India, where most of the world's supply is grown and distilled. Like all palmarosa it is overwhelmingly geraniol, which is why it smells of roses rather than grass. At a tenth of a percent it stopped yeast growing outright by breaking its cell membrane.^[1] It works against Fusarium and Aspergillus moulds too, which is part of why it turns up in skincare.^[2]

Gingergrass

Cymbopogon martinii var. sofia

Also Known As: Sofia Grass, Rusa Grass
Family: Herbal
Perfumery Note: Top
Intensity: Medium
Extraction: Steam Distillation
Plant Parts: Leaves, Grass
Origins: India, Nepal
Effect: Grounding & Centering, Focus & Mental Clarity, Energy & Uplifting
Aroma: Fresh, Ginger-like, Lemony
Applications: Diffusing & Inhalation, Massage & Body, Perfumery & Fragrance Making
Price: $$$$A wild-growing grass in India; high oil content makes it an affordable "earthy" oil

Gingergrass is palmarosa's wild cousin, the same species growing untended. It makes perillyl alcohol and phellandrene instead of geraniol, so the rose disappears and something sharper and gingery takes its place. It is treated as the lower grade of the two, and priced accordingly. Whether that is fair depends on what you want, since the two smell almost nothing alike. Testing found the oil active against bacteria, with the balance of compounds shifting as the grass matures.^[6]

Essential Nose

Palmarosa

Lemongrass

Rosha Grass

Gingergrass

References