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Malti🌬️ Wind-Driven Seed Dispersal
Samara 'helicopter' seeds and dandelion pappus parachutes drift under turbulent wind; compare autorotation and drag-parachute dispersal strategies and see the resulting landing-distance distribution.
How it Works
Seeds are released from a parent-plant point whose height is set by the release-height slider. Orange samaras autorotate as they fall: their spin rate builds up over the first moments of flight and generates a lift term that reduces effective gravity, so they descend at a moderate, fairly steady rate while drifting only modestly with the wind. White pappus seeds instead fall under heavy aerodynamic drag with almost no spin, giving them a very low terminal fall speed — because they stay aloft far longer, even a light wind has much more time to carry them sideways before they touch down.
Horizontal wind is the sum of a constant base speed and a turbulent gust term that evolves as a smoothed random walk, controlled by the gustiness slider, so the wind never blows perfectly steadily. Each seed's horizontal velocity relaxes toward the current wind speed at a rate set by its own drag coefficient — high for pappus, low for samara — which is why pappus seeds track gusts almost immediately while samaras lag behind. When a seed reaches the ground its horizontal landing distance from the release point is recorded into a running histogram at the bottom of the canvas, letting you compare the two dispersal strategies' distributions directly.
Samara: spin → 1 (ramp); vy = min(vy + g/(1+spin·2.2), vyMaxSamara)
Pappus: vy = min(vy + g·0.12, vyMaxPappus)
Horizontal: vx += (wind - vx) · dragCoefficient
Frequently Asked Questions
What is a samara seed?
A samara is a winged seed, like those from maple or ash trees, whose asymmetric shape causes it to autorotate as it falls, generating lift that slows its descent and lets wind carry it further from the parent tree.
What is a pappus?
A pappus is the parachute-like tuft of fine bristles attached to seeds of plants like dandelions. It creates very high drag relative to the seed's weight, so the seed falls extremely slowly and spends a long time exposed to wind.
Why do pappus seeds travel further than samaras on average?
Because a pappus seed's terminal fall speed is so low, it stays airborne far longer than a spinning samara, and that extra time in the air lets even modest horizontal wind carry it a much greater total distance before it lands.
What does autorotation do for a samara seed?
As a samara spins, its rotating wing generates an aerodynamic lift force similar to a helicopter rotor, which partially cancels gravity and reduces the seed's terminal fall velocity compared to a non-spinning object of the same mass.
What does the gustiness slider change?
Gustiness controls how strongly the wind speed randomly fluctuates around its base value over time, modelled as a smoothed random walk, which adds realistic turbulence and makes individual seed landing spots less predictable.
About this simulation
The orange "helicopters" and pale parachutes falling on screen are running two completely different survival strategies for the same problem — getting a seed away from a parent plant's shade. Watching the growing histogram at the bottom of the canvas split into an orange cluster near the trunk and a pale tail stretching far to the side reveals why dandelions can colonise a lawn in a single windy afternoon while maple seedlings tend to sprout close to the parent tree.
🔬 What it shows
Two seed dispersal strategies, autorotating samaras and high-drag pappus parachutes, falling through a turbulent wind field and building up a landing-distance histogram that reveals their very different dispersal ranges.
🎮 How to use
Click the canvas to release a seed at the current height, or set an Auto-release Rate for continuous releases; raise Wind Speed and Gustiness to see the pappus tail stretch out much further than the samara cluster.
💡 Did you know?
Some dandelion pappus seeds have been measured travelling well over a kilometre on strong winds, aided by a tiny separated-vortex ring that forms above the bristles and roughly doubles the drag a simple parachute shape would produce.
Frequently asked questions
What is a samara seed?
A samara is a winged seed, like those from maple or ash trees, whose asymmetric shape causes it to autorotate as it falls, generating lift that slows its descent and lets wind carry it further from the parent tree.
What is a pappus?
A pappus is the parachute-like tuft of fine bristles attached to seeds of plants like dandelions. It creates very high drag relative to the seed's weight, so the seed falls extremely slowly and spends a long time exposed to wind.
Why do pappus seeds travel further than samaras on average?
Because a pappus seed's terminal fall speed is so low, it stays airborne far longer than a spinning samara, and that extra time in the air lets even modest horizontal wind carry it a much greater total distance before it lands.
What does autorotation do for a samara seed?
As a samara spins, its rotating wing generates an aerodynamic lift force similar to a helicopter rotor, which partially cancels gravity and reduces the seed's terminal fall velocity compared to a non-spinning object of the same mass.
What does the gustiness slider change?
Gustiness controls how strongly the wind speed randomly fluctuates around its base value over time, modelled as a smoothed random walk, which adds realistic turbulence and makes individual seed landing spots less predictable.
Samara 'helicopter' seeds and dandelion pappus parachutes drift under turbulent wind; compare autorotation and drag-parachute dispersal strategies and see the resulting landing-distance distribution.
2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install