Know Your Natives – Crow Poison

Crow poison (Nothoscordum bivalve) of the Onion (Alliaceae) family (formerly of the Lily (Liliaceae) family) resembles a wild onion and is often called “false garlic,” but the species has neither garlic nor onion scent or taste. The genus name is actually derived from Greek words for “false” and “garlic.” The specific epithet means “two sides” or “two valves” in reference to a pair of bracts on flowering stems. Crow poison occurs primarily in a large area from Arizona, through Texas to Kansas, through Illinois, Ohio, to Virginia, and south to the Atlantic and Gulf Coast. The species also occurs in Central and South America. The only native Nothoscordum species in Arkansas, N. bivalve occurs statewide. Habitats are quite variable and include dry to mesic rocky to sandy to silty areas with partial to full sun, such as, prairies, woodlands, glades and barrens, and even in domestic lawns.

Crow poison is an herbaceous perennial growing from a globose bulb about ½ inch long and wide. Along with annual production of new fleshy roots, leaves, and inflorescence, plants also produce small, basal bulblets, which separate from the parent bulb before producing independent roots and leaves. Clonal clumps tend to develop. In a favorable site, due to self-seeding, a large colony of various-sized clumps may develop.

Photo 1: A clonal clump growing in a rocky, partially sunny site. Photo – March 22.

New leaves consist of an above-ground blade and a fleshy tubular base. As additional new leaves grow within the tubular base of the previous leaf, older leaf bases are pushed outward. While leaf blades die at the end of the growing season, thickened leaf bases persist for water and nutrient storage, resulting in bulbs. Outermost leaf bases become thin and brown and form a protective tunic before they disintegrate.

Each year, a mature bulb produces a few to a half-dozen fleshy, rather succulent, rather grass-like, slightly twisted, linear leaves, in-folded along most their length, but flattened toward the tip. Larger blades may be 10 inches long and ⅛+ inch wide. Bulbs also produce one or two pale green flowering stems (scapes) in early spring and often again in the fall. These rise to 10+ inches long and gradually taper to the inflorescence. 

Photo 2: Larger bulb on left has two stems (marked by red asterisks) which grow with the leaf cluster, but not at the cluster’s center. Bulbs at left (3/8 inch diameter) and right are producing bulblets (white bulge at base). Once separated, bulblets produce their own leaves and roots, as seen at lower left. Photo – March 8.

The inflorescence, umbels to 1½ inches wide, consists of three to ten well-spaced flowers on long pedicels. Umbels are initially encased in two translucent (hyaline) membranes that ultimately dry and persist as subtending scarious bracts (the “bivalves” of the specific epithet). Flowers bloom sequentially over several days. Pedicels lengthen until fruit has set, the final length about 2 inches. 

Photo 3: Umbels emerge from protective membranes. Membrane of stem second from left is ½ inch long. Flowers of an umbel tend to develop sequentially. Photo – March 10.
Photo 4: The rather succulent, narrowly linear, basally in-folded blades have the same appearance above (left) and below (right). Umbels are subtended by dried membranous bracts. Photo – March 31.

Flowers of crow poison open on warm sunny days and remain for several days, depending on weather (closing on cloudy days). The ½- to ¾-inch-wide flowers have 6 tepals (3 each nearly identical sepals and petals), six anthers and a pistil. Tepals are white with a yellowish glow on their interior base, ⅜+ inch long and ⅛ inch wide, elliptic to oblong, and apically acute, with an occasional notch at the apex, and a light greenish midvein. Tepals remain ascending (perianth does not become flattened). Stamens have tapered, translucent, light yellow filaments and bright yellow anthers with bright yellow pollen. Anthers are hinged in see-saw fashion at the filament tips. Stamens are adnate (joined) to the base of the tepals. The erect post-like style terminates with a flat, round stigma. The style attaches to the top of an ovoid, superior, 3-chambered ovary.

Photo 5: The six ascending tepals (sepals and petals) have a nearly identical appearance. At anthesis, tepals remain ascending.

The glabrous, green ovaries develop into smooth, 3-lobed, light tan capsules. The upper portion of dry (mature) capsules open along seams, and seeds drop out when stems are shaken or capsules disintegrate. Black, hard, globular seeds are about 1/16 inch wide.

Photo 6: Walls of the drying capsules become translucent before splitting open at the top, releasing the black seeds. Photo – May 1. (Squares = ¼ inch.)

Crow poison may be appropriate for a native plant garden or, more so, for a natural area. While individual clumps stay “tidy,” self-seeding may extend a colony further than desired. The plant is an early spring food source for small butterflies, bees and flies. Its grass-like leaves add textural variety to a garden. One non-native species of Nothoscordum, N. gracile (slender false garlic), has now been documented naturalizing in Arkansas. It has wider leaves (to 1/2 inch wide) and tepals that are connate (united) in their lower third. Like crow poison, slender false garlic does not have an onion or garlic scent.

Article and photographs by ANPS member Sid Vogelpohl

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