Shamrocks

By Adam Calder, Wheatsfield Produce Manager

Shamrocks are a traditional St. Patrick’s Day decoration, and a welcome, verdant addition to the produce department as the end of winter draws near.

What is a shamrock, though? As it turns out, that question does not have a straight forward or simple answer.

There are actually several species of plants that are colloquially referred to as “shamrocks.”  In Ireland, where the tradition originates, most people would agree that shamrocks are clovers.  All clovers are trefoils, or members of the Trifolium genus, and are three-leafed (with four-leafed clovers being exceptionally rare, hence the association with good luck). About half the people in Ireland consider Lesser Clover to be true shamrocks, a third of the population says it is White Clover, and the rest split between Red Clover, Black Medick, and Wood Sorrel.

Wood Sorrels, which are members of the Oxalis genus, are actually what we have for sale at Wheatsfield Cooperative.  They are sometimes known as False Shamrocks, but as there is no clear “true” shamrock, Wood Sorrel is often used.  The leaves and corms are edible, and taste acidic in a similar way to sorrel.  Oxalis plants contain oxalic acid, which can be toxic if eaten in large quantities, so it is best to consume oxalis in limited amounts.

The truly unique characteristic of oxalis is their leaves.  At sunrise, the leaves open up, and at sunset, they close.  Many plants “move” by growing toward or away from light, or phototropism.  The process by which oxalis leaves move is called photonasty.  Photonasty is different, and is movement as a response to turgor pressure (the water pressure inside the veins of plants.) This movement is too slow for the human eye to detect, but it can be observed with time-lapse photography.

If you are looking for a festive addition to Irish-up your home a little, or if you are looking for a unique houseplant with a surprising quality, then look no further than the Iowa-grown shamrocks we have at Wheatsfield.

Watch this stunning purple shamrock (Oxalis triangularis) wake up! This time-lapse captures the plant’s delicate heart-shaped leaves as they slowly unfurl and open, revealing their rich deep purple color. Nature’s daily magic, right on your windowsill. 🍀💜

Video by Adam Calder