Comandra umbellata ssp. umbellata

Bastard Toadflax

Comandra umbellata plant

Family - Santalaceae

Habit - Perennial forb, parasitic, with extensive network of deeply set rhizomes.

Stems - Ascending to erect, to 25 cm, simple to branching, glabrous.

Comandra umbellata stemStem and nodes.

Leaves - Alternate, simple, sessile or very short petiolate, entire, glabrous, variously oblanceolate to ovate, tapered at the base, narrowed to a pointed tip, to 0.7-5.0 cm long, 1 cm broad.

Comandra umbellata leavesStem and leaves.

Comandra umbellata leaf1Leaf adaxial.

Inflorescence - Dense, roughly umbellate clusters of flowers axillary in the uppermost leaves, these short-stalked, the whole inflorescence thus appearing as a leafy panicle, or paniculate, terminal clusters of 4-6 flowered cymules. Pedicels 1-4 mm long, glabrous.

Comandra umbellata inflorescence

Flowers - Perfect, epigynous, actinomorphic, the hypanthium 2-3 mm long, narrowly bell-shaped to obconical, with a prominent shallowly lobed nectary on the inner surface, glabrous. Sepals 5, 2-3 mm long, oblong-lanceolate to narrowly ovate, white, persistent at fruiting, usually minutely hairy on the upper surface and with a small tuft of longer hairs at the base, these hairs more or less fused with the adjacent anther. Petals absent. Stamens 5, attached opposite the sepals along the hypanthium rim, the filaments short, the anthers yellow. Pistil 1 per flower, usually of 3 fused carpels. Ovary inferior, 1-locular, the placentation free-central, with 2-3 ovules. Style 1, the stigma capitate.

Comandra umbellata flowerFlower.

Comandra umbellata flowers

Fruits - Nearly spherical 1-seeded drupes, 4-6 mm in diameter, dark brown at maturity.

Comandra umbellata fruitDeveloping fruit*
(*Fruit image of Comandra umbellata ssp. pallida, photographed in Arizona.)

Flowering - May - July.

Habitat - Upland woods and prairies, bluff tops, glades.

Origin - Native to U.S.

Lookalikes - None.

Other info. - This little plant is fairly common in dry, relatively undisturbed areas throughout Missouri, and is found across most of the upper Midwest and New England states. It is easily recognized in these habitats by its tight clusters of white flowers, leafy stems, and diminutive size. It is parasitic on neighboring plants by means of its rhizomes, which are tan, thin, and fairly long.

The plants found in Missouri can be assigned to the subspecies ssp. umbellata. The plant is also common in the western U.S., but as a different subspecies (ssp. pallida). This western subspecies has larger fruits, and leaves which are glaucous and have a bluish tint. A third subspecies, ssp. californica, is found even farther west. Some authors have placed these plants in their own family (Comandraceae).

The genus name Comandra derives from Greek for "male hairs," referring to hairs at the bases of the stamens. The common name "toadflax" appears to refer to the supposed habit of toads to shelter in the shade of a similar plant. "Bastard" in this context means "of unusual shape or size." The same common name has been used for European plants of the genus Thesium.

Photographs taken at Whetstone Conservation Area, Callaway County, MO., 4-26-04 (DETenaglia); also at Young Conservation Area, Jefferson County, MO, 5-2-2013, and Chiracahua National Monument, Cochise County, AZ, 5-26-2016 (SRTurner).


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