Spice Comparisons · Comparison
Flat-Leaf vs. Italian Parsley: Two Names for One Herb
Recipe says Italian parsley, shop label says flat-leaf? Buy it. They’re two names for the same herb: the Royal Horticultural Society lists “flat-leaved parsley,” “Italian parsley” and “plain-leaved parsley” as common names for one plant, and the University of Maryland Extension captions it “Italian or flat-leaf parsley.”12 It’s a form of Petroselinum crispum, the same species as curly parsley. The comparison that actually changes a dish is flat-leaf against curly, and there, oddly, one reference gives the milder curly leaf more essential oil.
One herb, several names
| Name you may see | What it refers to |
|---|---|
| Flat-leaf or flat-leaved parsley | The flat-leaved group of Petroselinum crispum |
| Italian parsley | Same plant; PROSEA files “Italian parsley” under the flat-leaved group312 |
| Plain-leaved parsley | Same plant (RHS); “Plain” and “Plain Italian Dark Green” are cultivar names in this group |
| P. crispum var. neapolitanum | The botanical variety name the RHS and Maryland Extension use for it12 |
| Chinese parsley | Not parsley: another name for cilantro, the leaf of coriander |
A note on the botanical name. PROSEA sorts cultivated parsley into three cultivar groups and lists var. neapolitanum, “or Italian parsley,” inside the flat-leaved group.3 Kew’s Plants of the World Online accepts only the species, Petroselinum crispum, and lists no separate variety for flat-leaf types.4 For a cook it comes out the same either way: the names describe one kind of leaf.
The comparison that matters: flat-leaf vs. curly
Cultivated parsley comes in three groups: curly-leaved, flat-leaved and turnip-rooted (Hamburg) parsley, which is grown for its root. So there are more than two kinds of parsley, though only two are common as fresh herbs.
| Flat-leaf (Italian) parsley | Curly parsley | |
|---|---|---|
| Species | Petroselinum crispum | Petroselinum crispum |
| Family | Apiaceae (carrot family) | Apiaceae |
| Native range of the species (Kew) | Northwest Africa and the Balkan Peninsula | Same |
| Leaves | Flat leaf blades on more open branches; the RHS calls them strongly aromatic and dark green | Curled leaf blades on compact branches; Britannica describes parsley leaves as either flat or deeply frilled |
| Flavor strength | Stronger flavored than curly (PROSEA)3 | Milder |
| Essential oil in the fresh herb | 0.04%3 | 0.07 to 0.15%3 |
| Leaf oil, German-grown samples | Myristicin 9.1%, limonene 18%, 1,3,8-p-menthatriene about 20%3 | Myristicin about 32%, limonene 14%, 1,3,8-p-menthatriene about 20%3 |
| Main use (PROSEA) | Mainly to flavor sauces, soups and stews | Garnishing and seasoning |
| Price | No dated, sourced retail comparison found | No dated, sourced retail comparison found |
The chemistry rows come from one reference and one set of German-grown samples. They show how the types can differ, not what’s in any bunch at the shop. They also show that “stronger flavored” doesn’t just mean “more oil”: PROSEA gives curly parsley the higher oil content and flat-leaf the stronger flavor.3 We found no source that explains the gap.
At the cutting board, flat-leaf tastes greener and more peppery. Curly is milder and more grassy, with a crisp texture that holds up as a garnish. PROSEA says flat-leaved parsley plays a role in Western cooking much like coriander leaves do in Asia.3
Can one stand in for the other?
- Flat-leaf and Italian parsley. Always, one for one. They’re the same herb.
- Curly for flat-leaf, or the reverse. Yes, though the dish will taste a little different. Ratio (Method): Use the same amount. If you’re using curly in place of flat-leaf where parsley is a main flavor, as in tabbouleh or a parsley sauce, taste and add more.
- Dried for fresh. See fresh vs. dried parsley and parsley substitutes for the attributed dried-to-fresh conversion and ranked alternatives.
Safety
Cooking amounts of parsley leaf aren’t a concern for most people. MedlinePlus lists parsley among foods that can change how the blood thinner warfarin works. Its advice isn’t to avoid them, but to keep the amount steady from day to day.5 See the parsley profile for more.
What isn’t known
- No source we found explains how the name “Italian parsley” came about or when it caught on in the United States, and we couldn’t trace the widely repeated stories about it rising with Italian restaurants.
- The myristicin and oil figures come from a single set of samples. We found no retail survey comparing flat-leaf and curly parsley.
Related
- Italian parsley vs. curly parsley
- Cilantro vs. parsley, chervil vs. parsley and basil vs. parsley
- How to store parsley, too much parsley and fines herbes
Footnotes
-
Petroselinum crispum var. neapolitanum, Royal Horticultural Society. rhs.org.uk · Reference work ↩ ↩2 ↩3
-
“Parsley”, University of Maryland Extension, 2023. extension.umd.edu · Reference work ↩ ↩2 ↩3
-
I.B. Ipor and L.P.A. Oyen, Petroselinum crispum, Plant Resources of South-East Asia (PROSEA). uses.plantnet-project.org · Reference work ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9
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Petroselinum crispum, Plants of the World Online, Royal Botanic Gardens, Kew. powo.science.kew.org · Reference work ↩
-
“Taking warfarin”, MedlinePlus, U.S. National Library of Medicine. medlineplus.gov · Regulator ↩
Also drawn on
- Parsley, Encyclopaedia Britannica. britannica.com
- Coriander, Encyclopaedia Britannica. britannica.com