Leonard’s skullcap

Leonard’s skullcap is a small, fairly common but easily overlooked, flowering plant. It occurs in the United States from Connecticut to North Carolina, west to Minnesota, eastern Kansas, and eastern Texas, and in southern Ontario Canada. There are only between 100 and 200 known occurrences of Leonard’s skullcap, but it is probably more common than those numbers indicate.

Leonard’s skullcap is found in upland prairies, savannas, openings in forests and woodlands, thinly wooded bluff tops and hillsides, abandoned fields, pastures, roadsides, and railroads. It grows under full or partial sun in dry, shallow, sandy or rocky, often alkaline (calcareous) soil.

Leonard’s skullcap is a perennial forb that rises on basal leaves and one or more stems from a short, horizontal, underground stem (rhizome) and often a spreading base. It can be 3″ to 12″ (8 to 30 cm) tall, but it is usually no more than 8″ (20 cm) in height. The rhizome develops tuber-like swellings at intervals, and it looks like a string of beads.

The stems are erect or ascending, sharply four angled, and leafy. They are usually unbranched, but sometimes they branch at the base. They are sometimes hairless, but they are usually sparsely to moderately covered with short, curved, non-glandular hairs.

Basal leaves are on short stalks. They are absent at flowering time. Stem leaves are opposite and 3⁄16″ to ¾″ (5 to 20 mm) long. The main stem leaves are stalkless and ⅜″ to ⅝″ (10 to 16 mm) long, and 2 to 3 times longer than wide. The leaf blades are lance-shaped to egg-shaped, broadly egg-shaped, or triangular egg-shaped. The base of each blade may be straight across (truncate), rounded, or slightly heart-shaped (cordate). The tip may be rounded or bluntly pointed. The upper surface is green and is sparsely covered with short, curved, non-glandular hairs. The lower surface is somewhat paler green and is moderately to densely covered with short, curved, non-glandular hairs. The largest leaves have a prominent midvein and 1 or 2 prominent side veins on each side. The margins are untoothed and distinctly rolled under.

The inflorescence is single flowers rising from the upper leaf axils. At each node, the two flowers face in the same direction. Each flower is on a very short stalk (pedicel). Each pedicel is about ⅛″ (3 mm) long and is covered with short, ascending hairs. The flowering period is May to June. On each plant, only 2 or 4 flowers will bloom at the same time.

Each flower is ¼″ to ½″ (6 to 12 mm) long. There are 5 outer floral leaves (sepals), 5 petals, 4 stamens, and 1 style. The sepals are fused into a tube (calyx) at the base and for most of their length, then separated into 5 lobes at the tip. The calyx is 1⁄16″to ⅛″ (2.0 to 3.5 mm) long when in flower, enlarging to ⅛″ to 3 ⁄16″ (4 to 5 mm) long when in fruit. It is greenish red and sparsely to moderately covered with short, curved, ascending, non-glandular hairs. The petals are mostly blue to bluish violet or bluish purple. They are united at the base into a long, narrowly funnel-shaped corolla tube and separated at the tip into 2 lips. The tube is slightly “S” shaped, bent up just above the calyx, and strongly curved at or just above the throat. The upper lip is unlobed and rounded. It forms a “skull”-shaped hood. The lower lip has a white patch at the throat with dark spots or mottling. It is spreading or arched, slightly longer than the upper lip, and shallowly 3-lobed. The lateral lobes are well developed and spreading. The lower lobe is broad, usually deeply notched, and often strongly bent downward. The outer surface of the corolla is minutely hairy, and the lower lip has two lines of scattered, fine hairs. The stamens have small anthers and do not project beyond the corolla tube. The style is branched at the tip and does not project beyond the corolla tube.

The fruit is a dry seed capsule (schizocarp) with 1 to 4 nutlets.

3″ to 12″ (8 to 30 cm)

Blue to bluish violet or bluish purple and white

Dry. Full or partial sun. Upland prairies, savannas, openings in forests and woodlands, thinly wooded bluff tops and hillsides, abandoned fields, pastures, roadsides, and railroads. Sandy or rocky, often alkaline (calcareous) soil.

May to June

Sources

2, 3, 4, 5, 7, 24, 28, 29, 30.

Native

Fairly common

Species
Some authors treat Leonard’s skullcap as the full species Scutellaria leonardi, following Epling (1942). Others treat it as one of three or four varieties of Scutellaria parvula, following Fernald (1945).

Variety
Scutellaria parvula var. missouriensis was previously classified as Scutellaria parvula var. leonardi, one of four varieties of small skullcap. Most authors now treat Scutellaria parvula var. leonardi as a synonym of Scutellaria parvula var. missouriensis. GBIF, World Flora Online, Plants of the World Online, and iNaturalist all recognize both varieties, with only var. leonardi occurring in Minnesota. MNTaxa recognizes the full species Scutellaria leonardi as well as Scutellaria parvula, the latter presumably var. missouriensis, with both species having identical distribution maps in Minnesota. Whether it is called Scutellaria leonardi, Scutellaria parvula var. leonardi, or Scutellaria parvula var. missouriensis, there is only one small skullcap that occurs in Minnesota.

Spelling
When the species or subspecies epithet leonardi is used, it is sometimes spelled leonardi with one “i”, sometimes leonardii with two “i”s.

Small black and white wasp feeding on Leonard's Skullcap...

Blossoms. It was so quick and came in on the top corner of the frame so I just cropped it best I could to show it. It was at Frenchman’s Bluff SNA.

Unusual Looking Small Plant...

This is an approximate actual size of this small low to the ground flowering plant I had never seen before. It almost looks like it has clam shaped attachments also growing on it. It was so small maybe 4-6 inches in height easy to not notice. It almost looks like those clam shaped parts of the plant are like a tiny fly or insect trapping plant but it is probably something else maybe how it seeds or something. I have no clue.

I found the little plant only in one spot and at a closer look quite unusual compared to many other small prairie plants. I tried to find this plant online but couldn’t. Felt you know way more about this sort of thing then I. The little plants had some sand speckled on them from recent wind and rain and the fact they are so low to the sandy type ground.

Flowering plant

Inflorescence

Fruiting plant

Fruiting plant

Infructescence

Scutellaria parvula var. missouriensis
wackybadger

Dan W. Andree
7/5/2024

Location:

Small black and white wasp feeding on Leonard's Skullcap... Blossoms. It was so quick and came in on the top corner of the frame so I just cropped it best I could to show it. It was at Frenchman’s Bluff SNA.

Dan W. Andree
Summer 2024

Location: Frenchman’s Bluff SNA

This is an approximate actual size of this small low to the ground flowering plant I had never seen before. It almost looks like it has clam shaped attachments also growing on it. It was so small maybe 4-6 inches in height easy to not notice. It almost looks like those clam shaped parts of the plant are like a tiny fly or insect trapping plant but it is probably something else maybe how it seeds or something. I have no clue.

I found the little plant only in one spot and at a closer look quite unusual compared to many other small prairie plants. I tried to find this plant online but couldn’t. Felt you know way more about this sort of thing then I. The little plants had some sand speckled on them from recent wind and rain and the fact they are so low to the sandy type ground.