Lomatium dissectum

fernleaf biscuitroot

Western North America (British Columbia to California, east to Colorado); dry rocky slopes, grasslands, sagebrush steppe; 500-7000 ft (150-2100 m)

Attracts Pollinators Attracts Butterflies Deer Resistant Drought Tolerant Fragrant (moderate)

Native to North America

SunFull Sun

WaterVery Low · drought-tolerant

HardinessZones 4–9

Overview

Lomatium dissectum is a herbaceous, tap-rooted perennial in the carrot family (Apiaceae spp.) reaching 24-48 inches (60-120 cm) tall with a spread of 18-24 inches (45-60 cm). The basal rosette is made up of finely dissected, fern-like leaves 12-24 inches (30-60 cm) long; individual ultimate segments are 1-3 mm wide, and the overall leaf is divided three to four times pinnately. Compound umbels 3-6 inches (8-15 cm) across are carried on stout, hollow stems from March through May. Flower color varies between the two recognized varieties: var. dissectum spp. is yellow, and var. multifidum spp. is purple-maroon. Both varieties carry the same umbel structure and bloom window of 4-6 weeks. Flat, winged fruits 10-15 mm long follow the flowers. The taproot is fleshy, aromatic, 12-24 inches (30-60 cm) deep, and 2-4 inches (5-10 cm) in diameter at the crown. Summer dormancy begins in July across most of the native range — the foliage dies back completely and the crown remains below ground until the following spring. Growth rate is slow, 3-5 years to flowering size. Hardy to USDA zone 4. Non-toxic. The species was a food and medicinal plant for Indigenous peoples across the Intermountain West.

Native Range

Lomatium dissectum is native to western North America, from British Columbia south to California and east to Colorado, in dry rocky slopes, grasslands, sagebrush steppe, and ponderosa pine understory at 500-7,000 feet (150-2,100 m).

Suggested Uses

Used in native plant gardens, dryland rock gardens, meadow plantings, and xeric borders in zones 4-9 at 18-24 inch (45-60 cm) spacing. The finely dissected foliage carries a soft texture in spring, and the compound umbels feed native bees and other pollinators. The species has cultural value to Indigenous peoples of the Intermountain West as a food and medicine plant. Summer dormancy leaves bare ground from July onward and the taproot makes the plant difficult to move once sited. Not suited to wet soils, irrigated perennial beds, or formal borders requiring year-round foliage.

How to Identify

Identified by the finely dissected fern-like basal foliage 12-24 inches (30-60 cm) long with ultimate segments 1-3 mm wide and the compound umbel inflorescences 3-6 inches (8-15 cm) across held on stout hollow scapes. Compared with Foeniculum vulgare (fennel), foliage is in a basal rosette rather than borne on tall leafy stems and the plant is dormant by July. Compared with other Lomatium spp. species, the leaf is cut to a finer division — ultimate segments 1-3 mm wide rather than the 3-8 mm typical of L. triternatum and L. utriculatum. Flower color of yellow (var. dissectum) or purple-maroon (var. multifidum) separates the two named varieties.

Appearance

Size & Dimensions

Height2' - 4'

Width/Spread1'6" - 2'

Reaches mature size in approximately 5 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~5 weeks

Spring

Compound umbels 3-6 inches (8-15 cm) across carried on stout hollow scapes above the foliage from March through May. Flower color varies between varieties: yellow (var. dissectum) or purple-maroon (var. multifidum). Bloom duration is 4-6 weeks. Flat winged fruits 10-15 mm long ripen through June.

Detailed Descriptions

Flower Description

Yellow (var. dissectum) or purple-maroon (var. multifidum); compound umbels 3-6 inches (8-15 cm) across on stout hollow stems

Foliage Description

Medium green, finely dissected, fern-like basal leaves 12-24 inches (30-60 cm) long; aromatic when crushed

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 8.0(Neutral)

357912

Soil Types

sand loam rocky

Drainagewell drained

Water & Climate

Water Needs

Very Low

Frost Tolerance

hardy

Time to Maturity

3-5 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Grows in full sun and dry to average, sharply drained soil at pH 6.0-8.0. Hardy to USDA zone 4. The taproot rots in wet or heavy clay soils and in irrigated beds. Drought-tolerant once established; supplemental summer water is not required and can shorten plant life. Transplanting is rarely successful because the taproot snaps; establish from fresh seed sown in autumn or from very young container-grown plants and leave undisturbed. Summer dormancy begins in July — bare ground remains until the following spring.

Pruning

Foliage dies back naturally as summer dormancy begins in July. Dead foliage can be removed in late summer once fully desiccated, or left in place to break down over winter. Division is not feasible — the deep taproot does not recover from being cut.