Scrophulariaceae

Figwort Family (sensu stricto)

Scrophulariaceae, the figwort family, as narrowly defined (sensu stricto) under the APG system, is a cosmopolitan family in the order Lamiales, now much smaller than historically conceived. It contains about 65 genera and roughly 1,800 species, primarily non-parasitic herbs and shrubs. Key remaining genera include Scrophularia (figworts) and Verbascum (mulleins). They typically have alternate or opposite leaves, flowers that are often subtly zygomorphic or nearly actinomorphic (sometimes strongly bilabiate), usually 4 or 5 stamens (often with hairy filaments), a superior ovary, and fruit typically a septicidal capsule with numerous seeds.

Scrophulariaceae example - Verbascum thapsus (Common Mullein)

Overview

The Figwort family has undergone one of the most dramatic revisions in modern plant classification. Traditionally a huge, morphologically diverse family defined largely by bilabiate flowers and capsular fruits, molecular phylogenetics revealed it to be highly polyphyletic. Consequently, the vast majority of familiar genera previously placed here (e.g., Penstemon, Veronica, Antirrhinum, Digitalis, Castilleja, Mimulus) have been transferred primarily to Plantaginaceae and Orobanchaceae, as well as smaller families like Phrymaceae and Calceolariaceae. What remains in Scrophulariaceae sensu stricto is a more cohesive group centered around genera like Scrophularia and Verbascum, along with others like Buddleja (butterfly bushes, sometimes placed in Buddlejaceae) and Limosella.

The redefined family remains cosmopolitan but is concentrated in temperate regions. Economically, its importance is reduced compared to its former scope, though Buddleja species are extremely popular ornamentals, and some Verbascum species have traditional medicinal uses or are significant weeds (like Common Mullein, V. thapsus). Plants in the strict sense family are non-parasitic, distinguishing them from the related Orobanchaceae. Flowers range from the nearly radially symmetric, rotate corollas of Verbascum to the distinctly two-lipped, often uniquely shaped corollas of Scrophularia.

Common Mullein (Verbascum thapsus) is a very common biennial weed in disturbed areas throughout Oklahoma (current location as of March 27, 2025), recognizable by its large, fuzzy basal rosette in the first year and tall flowering spike in the second. Native Figworts (Scrophularia marilandica) may also occur in woodland habitats.

Quick Facts

Scientific Name: Scrophulariaceae Juss. (sensu stricto)
Common Name: Figwort family
Number of Genera: Approximately 60-65
Number of Species: Approximately 1,700-1,900
Distribution: Cosmopolitan, primarily temperate regions.
Evolutionary Group: Eudicots - Asterids (Lamiids)
Order: Lamiales

Key Characteristics

Growth Form and Habit

Mostly annual, biennial, or perennial herbs; also includes shrubs (e.g., Buddleja) and rarely small trees. Plants are non-parasitic and typically autotrophic.

Leaves

Leaves are usually arranged alternately or oppositely (sometimes whorled). They are typically simple (rarely compound), with margins ranging from entire to toothed, crenate, or lobed. Stipules are absent. Leaves and stems are often covered in hairs, sometimes densely so (e.g., Verbascum).

Inflorescence

Inflorescence type is variable, commonly indeterminate structures like racemes, spikes (often dense, e.g., Verbascum, Buddleja), thyrses, or panicles. Flowers sometimes occur in axillary cymes or solitary.

Flowers

Flowers are usually bisexual and typically zygomorphic (bilaterally symmetric), although sometimes only slightly so, appearing nearly actinomorphic (radially symmetric, e.g., Verbascum). Flowers are usually 5-merous in the calyx and corolla, sometimes 4-merous.

Calyx: Composed of usually 4 or 5 sepals, typically fused at the base (synsepalous) with distinct lobes. Usually persistent in fruit.
Corolla: Composed of usually 4 or 5 fused petals (sympetalous). Corolla shape is variable: often rotate (wheel-shaped with a very short tube, e.g., Verbascum) or distinctly bilabiate (2-lipped), sometimes with a characteristic urn-like shape with a reduced upper lip (e.g., Scrophularia).
Androecium: Stamens typically number 4 or 5 (rarely fewer). When 5 (Verbascum), they are often slightly unequal in length, and filaments are frequently covered in conspicuous hairs. When 4 (Scrophularia), they are often didynamous (2 long, 2 short). Stamens are attached to the corolla tube (epipetalous) and alternate with the lobes. A fifth sterile stamen (staminode) is often present when only 4 fertile stamens occur, sometimes small and scale-like (Scrophularia) or filament-like. Anthers typically have two pollen sacs (thecae), sometimes confluent into one, opening by longitudinal slits.
Gynoecium: Ovary is superior, composed of 2 fused carpels, typically forming 2 locules (chambers). Placentation is axile, with usually numerous ovules attached to the central axis. A single terminal style is present, usually topped by a simple or capitate stigma, sometimes slightly 2-lobed.

Fruits and Seeds

The fruit is predominantly a capsule, characteristically dehiscing septicidally (splitting along the partitions between the locules), often appearing 2- or 4-valved as a result. Less commonly, the capsule is loculicidal or poricidal. It contains numerous, usually small seeds with endosperm.

Chemical Characteristics

Members often contain iridoid glycosides, saponins, and flavonoids. Cardiac glycosides, prominent in the now-excluded Digitalis, are absent from this core group. The chemistry aligns with other non-parasitic families in the Lamiales order.

Field Identification

Identifying Scrophulariaceae sensu stricto involves recognizing features common to the remaining core genera like Verbascum and Scrophularia, distinguishing them from the numerous genera now placed in other families.

Primary Identification Features

Non-Parasitic Herbs or Shrubs: Green, autotrophic plants.
Flowers Zygomorphic or Near-Actinomorphic: Often bilabiate (Scrophularia) or rotate (Verbascum), typically 4- or 5-merous corolla.
Sympetalous Corolla: Petals fused, at least at base.
Stamens 4 or 5: Attached to corolla tube, filaments often hairy (Verbascum), staminode often present if 4 stamens (Scrophularia).
Superior Ovary, 2 Locules: Ovary typically 2-chambered with axile placentation.
Septicidal Capsule: Fruit typically a capsule splitting along the partitions, containing numerous small seeds.

Secondary Identification Features

Leaf Arrangement: Alternate (Verbascum) or opposite (Scrophularia, Buddleja).
Hairy Stamens: Conspicuous hairs on stamen filaments (Verbascum).
Staminode Shape: Scale-like or filament-like sterile stamen (Scrophularia).
Rotate Corolla: Wheel-shaped flower with short tube (Verbascum).
Urn-shaped/Bilabiate Corolla: Unique flower shape in Scrophularia.
Dense Spikes/Panicles: Common inflorescence types (Verbascum, Buddleja).
Hairy Foliage: Common, especially dense woolly hairs (Verbascum).

Seasonal Identification Tips

Year-round: Basal rosettes of biennial Verbascum are distinctive with their fuzzy leaves. Woody Buddleja show opposite branching.
Summer: Peak flowering time for Verbascum (tall yellow spikes) and Scrophularia. Buddleja flowers profusely through summer.
Fall/Winter: Persistent dry capsules and flower stalks, especially the tall stalks of Verbascum, remain visible.
(Current Time Context: Late March in Oklahoma - Basal rosettes of Common Mullein (Verbascum thapsus) are likely prominent. Scrophularia would be vegetative).

Common Confusion Points

Plantaginaceae (Plantain Family): Now contains most former 'scrophs'. Highly diverse; identification relies on recognizing genera now placed there (Penstemon, Veronica, Antirrhinum, Digitalis, etc.) and distinguishing them from the remaining Scrophulariaceae genera based on stamen details, capsule type, placentation differences, or unique features like the Plantago spike.
Orobanchaceae (Broomrape Family): Also contains former 'scrophs'. Key difference: All members are parasitic (hemi- or holo-).
Lamiaceae (Mint Family): Usually square stems, opposite leaves, ovary deeply 4-lobed, fruit 4 nutlets.
Verbenaceae (Vervain Family): Often opposite leaves, zygomorphic flowers, superior ovary, but fruit usually drupes or schizocarps.
Bignoniaceae (Trumpet Creeper Family): Mostly woody, often opposite compound leaves, different capsule/seed structure.

With the family greatly reduced, identification often comes down to recognizing the key remaining genera (Verbascum, Scrophularia, Buddleja) or confirming the combination of non-parasitic habit, specific floral formula (4-5 stamens, often hairy or with staminode), 2-locular superior ovary, and septicidal capsule.

Field Guide Quick Reference

Look For (Scrophulariaceae s.s.):

Herb or shrub, non-parasitic
Leaves alternate or opposite
Flowers zygomorphic or near-actinomorphic
Corolla sympetalous (rotate, bilabiate)
Stamens 4 or 5, often hairy; staminode often present
Ovary superior, 2-locular, axile placentation
Fruit a septicidal capsule

Key Genera Examples:

Verbascum: Rotate corolla, 5 hairy stamens, often biennial rosette/spike
Scrophularia: Bilabiate/urn-shaped corolla, 4 stamens + scale-like staminode
Buddleja: Shrub, dense spikes/panicles, 4 stamens
Limosella: Small aquatic/mudflat herb

Notable Examples

The redefined Figwort family includes common weeds, popular garden shrubs, and less familiar herbs.

Verbascum thapsus

Common Mullein

A widespread biennial herb native to Eurasia, now a common weed of disturbed ground, fields, and roadsides globally, including Oklahoma. Forms a large rosette of thick, densely woolly gray-green leaves in the first year. In the second year, sends up a tall, stout spike densely covered with yellow, 5-petaled, nearly radially symmetric flowers with 5 stamens bearing orange hairy filaments.

Scrophularia marilandica

Late Figwort / Carpenter's Square

A tall perennial herb native to eastern and central North America, potentially found in moist woods or thickets in eastern Oklahoma. Stems are distinctly square in cross-section (unusual for the family, mimicking Lamiaceae). Leaves are opposite and toothed. Produces large, open terminal panicles of small, uniquely shaped, reddish-brown and green flowers. Corolla is bilabiate/urn-shaped with a reduced upper lip; 4 fertile stamens plus a small, purplish, scale-like staminode are present.

Buddleja davidii

Butterfly Bush

A fast-growing deciduous shrub native to China, extremely popular in cultivation worldwide for attracting butterflies. Features opposite, lanceolate leaves often whitish-gray underneath. Produces dense, terminal panicles or spikes of numerous small, fragrant, tubular flowers with 4 spreading lobes, typically purple but also white, pink, or yellow in cultivars. Stamens 4. Often placed in Scrophulariaceae, sometimes segregated into Buddlejaceae.

Verbascum blattaria

Moth Mullein

A biennial herb native to Eurasia, naturalized as a weed in North America, including Oklahoma. Less robust and less hairy than V. thapsus. Forms a basal rosette. Flowering stem is slender, bearing a loose raceme of flowers that are either yellow or white, with purplish centers and stamens covered in purplish hairs. Capsule fruit is globose.

Limosella aquatica

Water Mudwort

A small, often mat-forming annual or perennial herb found in muddy shores, pond margins, and shallow water, with a wide but scattered cosmopolitan distribution. Features small, linear to spoon-shaped leaves often arising in tufts from creeping stolons. Produces tiny, solitary, whitish or pale lilac flowers on short stalks from the leaf axils. Corolla is bell-shaped or rotate, 5-lobed; stamens usually 4. Fruit a small capsule.

Phylogeny and Classification

Scrophulariaceae sensu stricto is a family within the core Lamiales order (Lamiids, Asterids). Its modern definition is a direct result of molecular phylogenetic studies that revealed the traditional, broadly defined Scrophulariaceae to be massively polyphyletic – meaning its members derived from multiple distinct evolutionary lines, with some groups being more closely related to families like Plantaginaceae, Orobanchaceae, or even Lamiaceae than they were to the type genus Scrophularia.

The current Scrophulariaceae represents one of these now well-defined lineages, centered around Scrophularia, Verbascum, and related genera, including the tribe Buddlejeae (Buddleja) and others. This redefined family is now monophyletic and sits within the complex network of closely related families in Lamiales. Its evolutionary history involves diversification primarily in temperate regions, development of characteristic floral forms (like the rotate corolla with hairy stamens in Verbascum or the specialized bilabiate structure in Scrophularia), and the retention of typical Lamiales chemistry like iridoid glycosides, but without the evolution of parasitism seen in its close relative Orobanchaceae.

Position in Plant Phylogeny

Kingdom: Plantae
Clade: Angiosperms (Flowering plants)
Clade: Eudicots
Clade: Asterids
Clade: Lamiids
Order: Lamiales
Family: Scrophulariaceae (sensu stricto)

Evolutionary Significance

The story of Scrophulariaceae's reclassification is a landmark example of how molecular data revolutionized plant systematics, dismantling a large, morphologically convenient but evolutionarily artificial group. Scrophulariaceae sensu stricto now represents a more natural evolutionary lineage within Lamiales. Studying the remaining genera helps understand diversification patterns within this specific clade, focusing on variations in floral morphology (related to pollination), capsule dehiscence, and chemical profiles, separate from the convergent evolution of similar flower shapes seen in the genera now transferred to Plantaginaceae and Orobanchaceae.