Family tree symbols and structure, explained simply

If you've ever tried to read (or draw) a family tree, you'll have discovered it has rules of its own: lines that mean different things, generations arranged in a particular order, and symbols nobody ever explained to you. Here's the simple explanation — and why, these days, you barely need to memorize any of it.

The basic structure: generations in levels

A family tree organizes people into horizontal levels, one per generation: you, your siblings and cousins on one level, your parents and aunts and uncles on the level above, grandparents above them, and so on. In the European tradition the tree "grows upward" (ancestors at the top), though descendant charts also exist — starting from one ancestor and working down to the present.

Two concepts worth telling apart:

• Direct line: your parents, grandparents, great-grandparents — the chain you descend from.
• Collateral line: siblings, aunts and uncles, cousins — they share ancestors with you, but you don't descend from them.

The lines and what they mean

• Horizontal line between two people: a couple or marriage.
• Vertical line dropping from a couple: descent — it connects to their children.
• Horizontal line joining siblings: groups them under their parents' line of descent.
• Double line (in classic diagrams): marriage; dashed line: unmarried or informal union.
• Line struck through with two slashes: separation or divorce.

The classic symbols

In traditional kinship diagrams (the ones genealogists use, and medical genetics too):

• Square = male; circle = female.
• Symbol struck through with a diagonal = deceased.
• Diamond = sex unknown or unspecified.
• Double line between spouses = consanguinity (related to each other).
• Roman numerals for generations (I, II, III…) and Arabic numerals for individuals within each generation.

The cases the textbook diagrams don't cover

Real families rarely fit the manual's perfect scheme. The common cases and how they're represented:

• Second partners: each union is drawn separately, with its own children hanging from each. Chronology (first partner on the left) helps readability.
• Adoptions: traditionally a dashed vertical line. What matters isn't the stroke — it's recording the real bond of upbringing.
• Single-parent families: the line of descent drops from one person. Completely normal in any tree.
• People you know little about: include them, with a question mark for whatever's missing. A documented gap is information — it marks where to keep digging.

The good news: you don't need to draw any of this anymore

All this notation was invented to solve a paper problem: how to compress complex relationships into one static drawing. A digital tool solves it for you — you record that Ana and Luis were a couple, that they separated, and that they had two children, and the tree draws itself, correctly, every time.

In Familion, relationships are recorded as what they are (parents, partners, separations, children of each union) and the tree is generated automatically: no templates, no crossing lines, no impossible drafts. You can see how it looks with a sample family in the demo — no sign-up needed.

Frequently asked questions

Which way does a family tree "grow"? Most common today: ancestors at the top, new generations below. What matters is consistency.

How many generations fit in a family tree? On paper, about four or five before it becomes unreadable. Digitally there's no practical limit — you navigate with zoom and per-branch filters.

How do I show a current partner and an ex at the same time? Record both unions, with the separation marked on the old one. It's exactly the kind of case where paper gives up and digital shines.

Forget the symbols: record your family as it really is at familion.app and let the tree draw itself.