Cardamine angustata, slender toothwort, is a small native perennial herbaceous plant that lives in the woods and blooms in spring with white to pinkish flowers. It is a true spring ephemeral. It blooms before the trees leaf out and is gone in 4 to 5 weeks.
Cardamine angustata has had some name upgrades. Its previous genus was Dentaria and its previous species was heterophylla giving: Cardamine heterophylla and Dentaria heterophylla.
Cardamine angustata is in the NJ "List of Endangered Plant Species and Plant Species of Concern" (May 2022) as S3 meaning that it is rare in NJ. Also it is G5 indicating that it is secure globally.
Flowers
Inflorescence/Flower cluster:
The Cardamine angustata flower cluster forms a raceme (a single stem with short flower stalks). The flowers are clustered mainly at the top of the stem.
Individual Flower:
The slender toothwort flowers are white to pale pink and about 1 inch long. The flower has 4 sepals, 4 petals, 6 stamens (male) and one pistil (female) with a slender style. The close-ups show the anthers (male) are still green, immature, and are not releasing pollen yet. It is difficult of see all 6 of the anthers at the same time.
From the photos one can not tell if the stigmas (female) are or are not be ready to receive pollen from other plants. However, protogyny (stigma matures before anthers) is common in mustards (Cruciferae family) and in some Cardamines which are members of the mustard family
leaves
There are 4 toothwort species in NJ and the flowers are similar. It is the leaves that help distinguish between the species. Slender toothwort has both rhizomal & cauline leaves. These two kinds of leaves are distinctly different.
Rhizomal leaves: Rhizomal leaves are leaves that emerge from the underground rhizomes (horizontal underground stems). These long stemmed leaves emerge first. The flower stalks emerge separately from the rhizomes and are not attached to the rhizomal leaves.
Each leaf has 3 broad leaflets and each leaflet has 2 or 3 lobes. The lobe margins may be lobed, dentate, or crenate and may have sharp spines at the ends. The leaflet lobes are about an inch long.
In the photo below, each leaf is cut completely giving 3 leaflets each with a short stem. Each leaflet has 2 or 3 lobes and some edges are slightly toothed and some with little sharp teeth at the ends.
The leaf shapes are somewhat variable sometimes with sharper lobes.
In this photo, the long leaf stems (pedicels) can be seen.
Cauline leaves: Cauline leaves are leaves that grow along the stem. There are 2 to 3 cauline leaves below the flowers that are almost opposite. Each leaf has 3 leaflets that are narrow and may be toothed. The plant stem (flower stem) with the cauline leaves emerges separately and after the rhizomal leaves. The cauline leaves and the rhizomal leaves are very different and are an identification feature.
In the photo below, some flower stems with buds and cauline leaves emerge among the bunches of rhizomal leaves.
Plant
The plant grows to about 8 to 16 inches tall.
Underground the plant has rhizomes which are stems that grow horizontally and can send up rhizomal leaves and flower stalks for new plants and send down roots. Several plants can be connected underground by rhizomes.
The photos below show plants with cauline leaves and the rhizomal leaves nearby. The rhizomal leaves are broad and the cauline leaves are narrow.
Habitat
Habitat: moist forests.
Text by Millie Ling and all photos by Hubert & Millie Ling. Photos: flowers 4/16/2019, Somerset County
Additional information
Additional information / references:
- The USDA website shows Cardamine angustata distribution in the US and other information: https://plants.usda.gov/home/plantProfile?symbol=CAAN11
- Flora of North America - Cardamine angustata http://dev.floranorthamerica.org/Cardamine_angustata
- NatureServe - rarity information: https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.154523/Cardamine_angustata
- Maryland Biodiversity Project - lots of photos: https://www.marylandbiodiversity.com/species/viewSpecies.php?species=2914&showAll=1