TOOTHWORT
Cardamine concatenata (car-DAM-u-nee)
Brassicaceae (brass-i-KAY-see-ee), the Mustard or Cabbage Family
This humble little fellow is one of our favorite spring ephemerals. If you’ve never seen a Toothwort before, here’s a short VIDEO (2:13) which introduces it fairly well. Notice that the presenter still calls it by its old name “Dentaria laciniata“.
The leaf of the Toothwort is unusual and easy to recognize. In fact the leaves are so recognizable that we could probably just ignore the flowers. Here are 3 leaf characteristics:
- Each toothy leaf is attached to the stem by a long petiole.
- On plants with flowers, the leaves appear halfway up the stem in a whorl of 3.
- Depending on how you count them, each palmate leaf has 3 or 5 fingerlike lobes. It looks a bit like a marijuana leaf (which has 7 lobes).
Although the leaves alone can tell us that the plant is a Toothwort, it’s good to take note of the fragrant little flowers because they will help us identify other plants in the mustard (Brassicaceae) family. After all, we have more than 40 Mustard Family plants in the St. Louis area, so we’ll need to know what the flower looks like.
Flower Features of Toothwort
Inflorescence
The inflorescence is a loose, floppy terminal raceme with longish pedicels. The raceme elongates as the flowers open (typical of the brassicas)
Perianth
Calyx: There are 4 greenish/purplish sepals
Corolla: There are 4 petals. Not many families have only 4 petals. Those 4 petals form a cross, or “cress”. (That’s why some of our other local Brassica plants have names like “Bittercress”, “Rockcress”, “Gladecress”, “Watercress”, and “Pennycress”.)
Androecium
Stamens: There are 6 stamens with yellow anthers. 4 of the stamens are taller, 2 are shorter. This is useful to remember because it will help us identify other Brassicas out in the field. Flowers with 4 petals and 6 stamens (4 tall + 2 short) = Brassicaceae. (Imagine four big cabbages marching down the street “Hup-2-3-4, Hup-2-3-4” and two little Brussels sprouts running behind with their little legs trying to keep up.)
Gynoecium
Ovary: superior position
Carpels: 2 united carpels with a single style
Stigma: ball-shaped
Fruit: Typical of the Brassicaceae, the fruit is a long, skinny, 2-chambered pod called a “silique”. Inside the fruit, the 2 valves are partitioned with a thin septum. In late spring our Toothwort’s siliques will turn brown and twist open to eject their dozen or so seeds.
Our Cutleaf Toothwort isn’t the only Cardamine that lives in the St. Louis area. We’ve got 5 of them! Click on the following links to MissouriPlants.com so that you can compare them.
- Cardamine bulbosa (Bulbous Bittercress)
- Cardamine concatenata (Cutleaf Toothwort)
- Cardamine hirsuta (Hairy Bittercress)
- Cardamine parviflora (Small-Flowered Bittercress)
- Cardamine pensylvanica (Pennsylvania Bittercress)
Of these, only our poor little Cutleaf Toothwort has such gawky leaves – so gawky that they’ve earned him the unfortunate common name “Crow’s Toes”.
The Toothwort’s stem rises up from a rhizome (an underground stem). Those rhizomes are edible and are said to taste like horseradish (another Brassica). Some people say they put them in their soups and salads. But those Toothwort rhizomes take years to grow, so using them for a fun food doesn’t seem very responsible.
The Brassicas are early bloomers. There are at least 9 white ones that are already beginning to flower in St. Louis:
- Boechera (Arabis, Borodinia) laevigata (Smooth Rockcress)
- Capsella bursa-pastoris (Shepherd’s Purse)
- Cardamine concatenata (Cutleaf Toothwort)
- Cardamine hirsuta (Hairy Bittercress)
- Draba cuneifolia (Wedgeleaf Draba)
- Draba reptans (Creeping Draba)
- Draba verna (Spring Draba)
- Leavenworthia uniflora (One-Flowered Gladecress)
- Thlaspi arvense (Field Pennycress)
If we can get familiar with these 9 plants, we’ll know most of the confusing white Brassica flowers we encounter for the next few weeks. It’s still a bit early for the beautiful Yellow Rockets (Barbarea vulgaris) to bloom.
Now for some bad news. Garlic Mustard is an invasive plant from the Cabbage Family that is causing lots of problems. The photo is of the troublemaker is shown below.
Alliaria petiolata (al-ee-AR-ee-uh) is the name of this non-native, invasive plant that is choking out our forest undergrowth and crowding out wildflowers – including (and especially) its very own cousin Toothwort. It has a garlicy flavor (unusual in a broadleaf plant) that some people find tasty. But the plant is so destructive that it shouldn’t even be planted in a garden. (To help remember the genus name “Alliaria”, picture the plant out in the ALLEY, singing an ARIA.)
If we protect our natural areas from habitat fragmentation and from the encroachment of its nemesis Garlic-Mustard, we’ll be able to enjoy our homely little Toothwort for years to come.
Flower-Spotter Week #1 (March 20-26)
Please protect the plants in our natural areas. Toothwort might be found in the following locations:
[BABL, CUIV, DONR, GLAS, GRAM, HAWN, LABQ, LITL, MERA, ONON, POWD, SHAW, STFR, VALV, WASH, WELD, YUNG]
Please click to see a list of all our St. Louis Brassicaceae plants.