Hypogynous, perigynous, epigynous: how do I tell them apart, and what is "superior" or "inferior" ovary?
Aarav Kulkarni11th Sample
17 Sept 2026 · 1 min read
I made a checklist for the flower chapter and it has 14 items. I could tick 11. The last three are all the same topic: insertion of floral parts on the thalamus. 😬
From NCERT, I know: in hypogynous flowers the gynoecium occupies the highest position and the other parts are below it. In epigynous flowers the margin of the thalamus grows upward, encloses the ovary completely, and gets fused with it, and the other parts arise above the ovary. In perigynous flowers the gynoecium is in the centre and the other parts are on the rim of the thalamus, at the same level.
I can say the definitions. But when I see the diagrams in the book they look so similar. And NCERT then says ovary is "superior" in hypogynous, "half inferior" in perigynous and "inferior" in epigynous, and I don't see why they use these words when the flower is the one with different insertion.
I also have a half-learned section on symmetry: actinomorphic vs zygomorphic vs asymmetric, with examples I keep swapping. Can someone give me a quick method to decide and the standard examples? I am a list person, give me lists please 🙂
7 answers & replies
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[+][–]Diya Menon11thSample· 1mo ago
ahh I love this, I grow all these in pots!! 🌺 Think of the ovary as the "baby" and the rest of the flower as the "clothes":
- Hypogynous: clothes (sepals, petals, stamens) start below the ovary. Ovary = superior. Mustard, china rose (Hibiscus), brinjal.
- Perigynous: clothes are on the rim of a cup-like thalamus around the ovary, at about the same level. Ovary = half inferior. Rose, plum, peach.
- Epigynous: the thalamus fuses with the ovary wall and the clothes start above the ovary. Ovary = inferior. Guava, cucumber, and the ray florets of sunflower.
[+][–]Yash Tiwari11thSample· 1mo ago
class 11 me again. i remember guava as perigynous, because guava is a "fruit with the cup shape", just like rose and peach. ok?
[+][–]Lakshmi TripathiDropperSample· 1mo ago
Guava is epigynous, Yash. The rose, plum and peach are perigynous (the thalamus is cup-shaped, but the ovary is not fused with it). In guava and cucumber, the thalamus is fused with the ovary completely, so the ovary is inferior and the petals sit on top of it. Quick check: the crown of dried petals/sepals at the top of a guava fruit shows the other floral parts were above the ovary. That's the clue for epigyny.
[+][–]Aarav Kulkarni11thSample· 1mo agoAuthor
okay the "crown at the top of the guava" test is so good. I checked a guava in the kitchen just now and yes, there it is. ticking all 14 items now. thanks everyone!
[+][–]Pooja Iyer12thSample· 1mo ago
Mnemonic: HYPO = below (like hypodermic, under the skin). EPI = upon (like epidermis, upon the skin). PERI = around (like perimeter). It's about where the other parts are relative to the ovary.
Symmetry list: actinomorphic (radial, can be cut into two equal halves by any vertical plane through the centre) - mustard, datura, chilli. Zygomorphic (bilateral, only one plane) - pea, gulmohur, bean, Cassia. Asymmetric (no plane) - canna.
[+][–]Ishita GoyalDropperSample· 1mo ago
Extra from the chapter that goes with this, in my template:
Term Meaning Bracteate / ebracteate flower with / without bracts Trimerous, tetramerous, pentamerous floral appendages in multiples of 3, 4, 5 Complete / incomplete all four whorls present / at least one missing Bisexual / unisexual both androecium and gynoecium / only one Tepals when calyx and corolla look alike and are not distinct, e.g. lily Perianth = calyx + corolla together. [+][–]Siddharth RaoDropperSample· 1mo ago
The NEET trap here is usually the match-the-following: Hypogynous ↔ superior ovary, Perigynous ↔ half inferior, Epigynous ↔ inferior. And the example trap: people put peach/plum/rose as epigynous because the fruit looks "fused". Don't. Rose, plum, peach = perigynous. Guava, cucumber = epigynous. If it says "mustard, brinjal, china rose", it's hypogynous.
