A card game from the Philippines wants to teach organic chemistry, one tawa-tawa at a time

On a wooden laboratory bench in Manila, a deck of illustrated cards does something the periodic table has rarely managed: it makes tawa-tawa, a low-growing herb that thrives in open grasslands, behave like a celebrity. Players draw it and learn that behind the plant sits a working pharmacology, the kind that has been quietly studied for decades by Filipino ethnobotanists and largely ignored by chemistry classrooms. The card game, called Herbularyo, is the product of an effort to drag that body of knowledge out of herbarium cabinets and into the hands of students who might otherwise never pick up an organic chemistry textbook.

Herbularyo arrives at a moment when the gap between how science is taught in low- and middle-income countries and the cultural texture of the communities sitting in those classrooms is finally being treated as a design problem rather than a deficiency. The premise is straightforward: if the molecules in question are already known to your lola, why teach them as if they were imported from somewhere else? The game pairs medicinal plants that have anchored Philippine traditional medicine for generations, tawa-tawa prominent among them, with the organic-compound structures behind their reputed effects. The cards let a player hold both at once, the leaf and the molecule, and ask a question neither could provoke alone.

A deck that knows its own history

The plants in Herbularyo are not curiosities. Tawa-tawa, formally Euphorbia hirta, has been documented across South and Southeast Asia as a remedy for dengue-associated symptoms, and laboratory studies over the past two decades have pointed at flavonoids, tannins and terpenoids as plausible bioactive candidates. That body of work sits in regional journals and doctoral dissertations, not in the glossy exports of Western pharmacopoeia. A Filipino student encountering it through a standard organic chemistry syllabus would likely meet it, if at all, as an unnamed example in a chapter on phenolic compounds.

The game reframes the encounter. Each card pairs a plant with a structural diagram of a representative molecule, plus short notes on traditional use and on what the laboratory evidence does and does not yet support. The deck's designers have been careful to keep the folk and the formal on the same page, neither reduced to a footnote of the other. Medicinal plants are presented as a credible starting point for chemistry questions rather than as colourful preludes to the real science.

That matters because the way a science is introduced shapes who feels entitled to extend it. When the canonical examples are uniformly imported, the implicit message is that the discipline belongs elsewhere and the local student is a tourist in it. Herbularyo is one of several recent efforts in the region to invert that signal: teach the chemistry of plants the student has already met in a backyard or a market stall, and the discipline stops looking like a foreign language.

The pedagogical bet

The design choice is unusually direct. Each turn of the game requires a player to match a plant to an organic compound class, or to assemble a structural fragment under a time pressure. The mechanics borrow from familiar match-and-trade card games, the kind Filipino households already play, so the cognitive overhead is in the chemistry, not in the rules. Early playtest reports from classrooms in Metro Manila describe students who had previously memorised functional groups without grasping their logic walking out able to argue, in plain language, why a particular flavonoid is plausibly anti-inflammatory.

The bet is that affect precedes abstraction. A student who already cares whether tawa-tawa works will read the structural diagram on the back of the card with a different attention than a student reading the same diagram in a textbook chapter on polyphenols. The same molecule, the same line and hexagon arrangement, lands differently when the pathway from leaf to laboratory is on the same piece of cardboard.

Risks the designers have to manage

The risk is the inverse of the bet. Pairing folk medicine and organic chemistry on a single card can slide, if handled carelessly, into the suggestion that traditional use is itself a clinical claim. The designers have flagged this themselves: the cards describe traditional use as a hypothesis-generating tradition, not as a verified treatment. The line between "this is why ethnobotanists study the plant" and "this is why you should drink the tea" is thin, and the game lives on it.

A second risk is academic. Philippine ethnobotany has produced serious work, but the international citation graph for that work is sparse. A card game that leans heavily on regional journals may draw the quiet criticism that its sources are local and therefore lesser. That criticism would be wrong on the evidence, but it is the kind of wrong that gets repeated. The designers' task is to make the citation trail legible without burying the game in footnotes.

What this is actually about

Read narrowly, Herbularyo is a chemistry card game. Read more honestly, it is part of a slow-motion argument about whose knowledge counts as a starting point for science, and whose does not. The Philippines has, like most of the Global South, a deep reservoir of botanical and pharmacological observation that never made it into the canonical teaching examples of the discipline. Most of that reservoir remains in herbarium cabinets, dissertations and field notebooks. A handful of researchers, a printer and a deck of cards have decided that one corner of it deserves a wider audience, and that the audience is already in the room.

The structural pattern is familiar in other fields: a body of evidence that the global citation system treats as provincial is treated by its own community as foundational. The contest between those two readings is rarely settled by argument. It is settled, when it is settled, by artefacts that force the second reading into the first. A playable deck, sitting on a laboratory bench in Manila, is one of those artefacts. The question worth watching is whether the discipline makes room for it.

How Monexus framed this: the wire coverage leads on a novelty beat. We led on the structural question, who gets to define the canonical examples of a science, and treated the game as evidence rather than as the story.