Funny, fervent botany for tree-curious minds.
Completely Arbortrary treats trees as portals into science, culture, and weirdly specific observation. Episodes move from yew toxins and redwood fog uptake to cherry wood history, fungal networks, sakaki flowers, and the practical stakes of protecting conifers.
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Completely Arbortrary is a tree show that treats botany as both serious science and excellent conversational material. It is loose, funny, and densely curious. A single species can carry an episode from plant anatomy to a joke about shoes, from seed chemistry to the stakes of protected land. The show does not present trees as background scenery. It treats them as active participants in complicated systems. English yew becomes a way to talk about toxicity, fleshy cones, birds, mammals, and the difference between eating fruit and destroying a seed. Douglas-fir becomes a long-view story about forests that overlap across generations, with roots grafting together and fungi shaping the underground world. Coast redwood becomes a fog story, where canopy leaves and summer drought explain how a giant survives in a narrow coastal belt. Wild whiskey cherry brings the human history closer: people finding valuable wood, clearing good farmland, and turning an abundant tree into something altered by appetite. Bigleaf magnolia invites beetles into the frame, with pollination described as a precise bargain rather than a vague natural process. The show can be silly. It often is. That looseness is part of the appeal, because the jokes sit beside genuine explanation instead of replacing it. The recurring language of fungal associates, cones, forests, flowers, and field obsession gives the show a lived-in texture. Recent episodes also frame Casey's Year of the Cone as a conservation-minded project to find native conifer species in the United States. That adds urgency without making the program dour. Completely Arbortrary works best for listeners who like science with digressions, specificity, and human enthusiasm left intact.
Made for: For listeners who like nature science, plant identification, ecology, and conversational shows that make room for jokes. It especially suits people who enjoy learning why one tree's flowers, cones, roots, wood, or habitat can explain a much larger world.
What sets it apart: The show combines close botanical detail with a loose comic rhythm, so technical ideas like fog uptake, root grafting, seed dispersal, and beetle pollination arrive through vivid, oddball conversation. Its tree-by-tree format gives each episode a concrete anchor while still reaching into conservation and deep forest time.
Tree advocate Casey Clapp and his tree-curious friend Alex Crowson bring you a podcast about trees and other related topics. History, culture, art, religion, science... trees affect and are affected by everything. Join Casey and Alex on their silly and educational journey to prove it.
Based on 6 episodes we listened to · September 2026
Species-by-species conversations turn tree anatomy, pollination, water uptake, and forest relationships into vivid, approachable plant biology.
Completely Arbortrary treats each tree as a working biological system with a cultural footprint. Casey Clapp and Alex Crowson build conversational lessons around particular species, following coast redwoods into fog-dependent water uptake and English yews into the chemistry and…
A beetle sleepover becomes Casey's pollination theory, and suddenly you're rooting for the deal.
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Short reviews from the PlayNext desk, based on the episodes we processed.
A conifer quest narrows to sakaki flowers and a memorable shoe comparison.
Casey Clap sets up the Year of the Cone as a one-year search for every native species of conifer in the United States, and the episode settles into plant talk through close observation rather than abstract framing.
Yew becomes a clear lesson in seed dispersal and plant tradeoffs.
Casey's Year of the Cone turns its attention to yew, using the tree to trace how conifers move seeds through a bargain with animals. The episode is strongest when it sticks close to plant logic: why fruit can surround a seed, why some creatures do the eating and the pooping, and…
A Douglas-fir conversation that turns one tree into a whole forest network.
The episode treats Douglas-fir as a window into a forest that works as one connected system. Roots, fungal associates, and tree-to-tree grafting all keep the focus on relationships instead of any single organism standing alone.
A cherry tree's timber history opens onto the ecological consequences of settlement.
Wild Whiskey Cherry follows a cherry tree at full height in the Eastern deciduous forest, with attention to the Pennsylvania, West Virginia, New York, and Allegheny Plateau area.
Fog and tree anatomy do the heavy lifting here.
This episode links tree biology to fog in a clear, grounded way, using the trees' fog-belt habitat from southern Oregon to Santa Cruz and their dimorphic leaves to show how they manage water and hold on along the coast.
A flower-and-beetle story that turns pollination into a sly bargain.
The episode settles into a focused plant story, moving through Casey's Year of the Cone project, the urgency around protected areas, and a close look at how one flower may be working a quiet bargain with beetles.
European plant wisdom, slowly gathered.
Close listening from the living world.
Lulu Miller and Latif Nasser build single reported stories around one scientific question.
Flora Lichtman interviews scientists, from gut-health researchers to Queen's Brian May.
Steven Novella and a rotating panel dissect weekly science news and debunk pseudoscience claims.
Long interviews with neuroscientists and philosophers on consciousness, decision-making, and whether AI is anything like a brain.
Casey Clap announces his Year of the Cone project to find all 111 native US conifer species in one year and asks for support.
Casey Clap announces his Year of the Cone project to find all 111 native conifer species in the US and invites support, then transitions to a live Arbitrary Plus episode with fungal associates.
Casey Clap discusses the black locust tree, its ecological role, and its controversial status as both a native and invasive species.
Casey Clap introduces his project to find all 111 native conifer species in the US in one year, emphasizing conservation and community support.
Casey Clap discusses his project to find all 111 native conifer species in the US in one year, while Alex Gross introduces the episode with a focus on Shinto and the Sakaki tree.
Completely Arbitrary's Tree Runs covers English yew in Hades!
Casey opens Completely Arbitrary by tying the farewell episode to Year of the Cone, a project to find all 111 native U.S.
On this episode of Completely Arbitrary, hosts Casey Clapp and Alex identify the wild whiskey cherry, better known as the black cherry (Prunus serotina), a tree native to the eastern United States.
Casey announces a break due to editor Alex's concussion and promotes his upcoming project, the Year of the Cone.
["Casey Clap frames the Year of the Cone as a one-year search for all 111 native U.S.
Casey Clap introduces his Year of the Cone project to find all 111 native conifer species in the US and discusses the importance of protecting their habitats.