Sedum ternatum Michx.

Three-Leaved Stonecrop


CC = 6
CW = 5
MOC = 24

© SRTurner

Family - Crassulaceae

Habit - Perennial forb from fibrous roots. Foliage and flowers often with faint, tiny, reddish brown resinous lines or dots.

Stems - Decumbent, to 40 cm, sometimes rooting at nodes, often forming loose mats, green, sometimes reddish-or pinkish-tinged, not or only slightly glaucous, the flowering and vegetative branches 5-15 cm long, erect or ascending.

Leaves - Opposite or in whorls of 3, sessile, attached just above the base, with a small, truncate plate of tissue below the attachment point, only slightly and gradually reduced in size toward the stem tip. Leaf blades thickened but flat in cross-section, the margins entire or inconspicuously scalloped, the surfaces dark green, sometimes yellowish-or pinkish-tinged, not or only slightly glaucous, those of the main stems and vegetative branches 4-25 mm long, 4-15 mm wide, broadly obovate to broadly elliptic or spatulate, rounded to truncate or shallowly notched at the tip, occasionally very bluntly pointed or with an abrupt, minute, sharp point; those of the flowering branches often slightly shorter or narrower.

Sedum_ternatum_basals.jpg Basal rosettes.

© SRTurner

Inflorescences - Terminal panicles with usually 3 branches, these spreading to loosely ascending spikelike racemes.

Sedum_ternatum_inflorescence.jpg Inflorescence.

© DETenaglia

Sedum_ternatum_inflorescence2.jpg Inflorescence branch.

© SRTurner

Flowers - Perfect, actinomorphic. Sepals 5, 2.5-5.5 mm long, fleshy, oblong-lanceolate to elliptic, bluntly pointed at the tip. Petals 5, 4.5-7.0 mm long, narrowly elliptic-lanceolate, white. Stamens usually 10, with the anthers red or purplish red. Pistil of 5 carpels, these free or fused at the base, more or less erect at flowering, sometimes spreading at fruiting, white, each with a tiny, scalelike nectary at the base. Nectaries somewhat longer than wide, oblong, yellow to nearly white. Ovaries superior, green to greenish white, each with 1 locule, with numerous ovules, the placentation more or less parietal. Styles 1 per carpel, the ovary tip tapered into the tapering style.

Sedum_ternatum_flowers1.jpg Flowers.

© SRTurner

Sedum_ternatum_calyces.jpg Calyces.

© SRTurner

Fruits - Follicles 3.5-6.0 mm long, spreading at maturity. Seeds 0.7-1.0 mm long, narrowly asymmetrically ovoid, finely longitudinally ribbed, dark brown.

Flowering - April - June.

Habitat - Bottomland and mesic forests, rock outcrops, rocky spring outlets, streambanks, shaded margins of glades, bases and ledges of bluffs, railroads, partially shaded disturbed areas; on both acidic and calcareous substrates.

Origin - Native to the U.S.

Lookalikes - None when in flower.

Other info. - This small creeping plant is found in scattered locations in the Ozarks, with a few populations also occurring in the northeast corner of the state. Beyond Missouri it is found mainly to our east, its range extending nearly to the Atlantic coast. It is easily identified as a Sedum by its creeping, succulent stems. The whorls of 3 leaves at each node and striking inflorescence branches with white flowers uniquely identify the species. The plant is rather uncommon. It favors moist, cool, rocky areas and would make an excellent garden subject in an appropriate area.

Photographs taken in Linville, NC., 5-11-03 (DETenaglia); also at Silver Mines Recreation Area, Madison County, MO, 7-4-2017 and 4-28-2020 (SRTurner).