This annual plant can achieve an impressive size. It closely resembles several Aureolaria spp. (False Foxgloves), which are also parasitic on the roots of oaks. The flowers of Mullein Foxglove are a little shorter than the flowers of the latter species (which can exceed ¾' in length), and the throat of its flowers are partially obstructed by an abundance of fine hairs. The flowers of the False Foxgloves are quite open at the throat because they lack these hairs. Another scientific name for Mullein Foxglove is Seymeria macrophylla.

This native plant is a summer annual about 2-6' tall. It branches regularly from the central stem, while the side stems branch very little. These stems are somewhat pubescent and green to reddish green. The opposite leaves are up to 12' and 4' across, becoming smaller as they ascend the stems. The lower leaves are pinnately lobed, cleft, and coarsely toothed, while the upper leaves are lanceolate-oblong and smooth along the margins. The petioles of the leaves become progressively shorter toward the apex of the plant; the upper leaves are often sessile. Both lower and upper leaves are hairless, or nearly so.  The upper stems terminate in spike-like racemes of yellow flowers. These racemes vary ½–3' in length, depending on the size of the plant. Each flower is about ½' long, consisting of a yellow tubular corolla with 5 spreading lobes and a green calyx with 5 blunt teeth. The tubular corolla is rather short and broad; its throat is partially obstructed by an abundance of fine yellow hairs. The two upper lobes of the corolla fold backward, while the 3 lower lobes function as a landing pad for visiting insects. The blooming period is mid-summer to early fall and lasts about 1½ months; only a few flowers are in bloom at the same time. Each flower is replaced by a seed capsule is globoid-ovoid; it eventually turns brown and contains several seeds. The root system consists of a taproot and secondary feeder roots. The feeder roots can attach themselves to the roots of oak trees; they suck moisture and possibly some nutrients from the host tree. Thus, Mullein Foxglove is partially parasitic. Reproduction is by seed.

Seymeria macrophylla Nutt.:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Dasistoma macrophyllum (Nutt.) Raf.:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

United States

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Global Range: WV & OH to south WS, IA & NE; south to north SC, G, AL, MS, & LA & northeast TX (Great Plains Flora Assoc., 1986).

Comments: Rich woodlands, often along streams.

The most important pollinators of the flowers are bumblebees, which suck nectar and collect pollen. Other long-tongued bees also visit the flowers, including honeybees and Miner bees. Occasionally, butterflies and skippers suck nectar from the flowers, but they are ineffective pollinators. The caterpillars of the moth Rhodoecia aurantiago (Orange Sallow) bore into the seed capsules and feed on the seeds. It possible that the foliage is eaten by the caterpillars of the butterflies Junonia coenia (Buckeye) and Euphydryas phaeton ozarkae (Baltimore). The latter variety of the Baltimore is confined to southern Illinois. Both of these butterfly species are known to feed on the foliage of Aureolaria spp. (False Foxgloves), which are closely related to Mullein Foxglove. Photographic Location

Dasistoma macrophylla (Mullein Foxglove)
(Long-tongued bees suck nectar or collect pollen; Syrphid flies feed on pollen & are non-pollinating; butterflies & skippers suck nectar & are non-pollinating; one observation is from Hilty, while the remaining observations are from Robertson)

Bees (long-tongued)
Apidae (Apinae): Apis mellifera sn; Apidae (Bombini): Bombus bimaculatus sn cp, Bombus impatiens sn, Bombus pensylvanica sn cp fq, Bombus vagans sn cp fq; Anthophoridae (Eucerini): Melissodes bimaculata bimaculata sn

Flies
Syrphidae: Milesia virginiensis fp np

Butterflies
Pieridae: Pieris rapae sn np; Papilionidae: Papilio cresphontes sn np (H)

Skippers
Hesperiidae: Poanes zabulon sn fq np

The following is a representative barcode sequence, the centroid of all available sequences for this species.


No available public DNA sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1

United States

Rounded National Status Rank: NNR - Unranked

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: Widespread. GRANK from T. Reznicek and M. Penskar (MIHP).

The preference is partial sun, mesic to dry conditions, and a loam, clay-loam, or rocky soil. This plant benefits from the proximity of oak trees. Its size is highly variable, depending on growing conditions. Range & Habitat