Andersonglossum spp.

wild comfrey

Boraginaceae North America

Attracts Pollinators Drought Tolerant

Native to North America

SunPart Shade – Full Sun

WaterLow · drought-tolerant

HardinessZones 3–8

Overview

Andersonglossum spp. is a small North American genus of three species of biennial to short-lived perennial herbs in the borage family, Boraginaceae, segregated from the Old World genus Cynoglossum spp.. Plants form a basal rosette of oblong to elliptic leaves 2-12 in (5-30 cm) long, softly hairy on both surfaces, from which rises an erect, sparsely branched flowering stem 12-40 in (30-100 cm) tall. The upper stem carries open, curving racemes of small five-lobed flowers 0.2-0.4 in (5-10 mm) across, pale blue to lavender, occasionally white, each with a short tube and rounded lobes. Flowering is followed by clusters of four nutlets covered in barbed prickles that catch on fur and clothing, dispersing the seed. The most widespread species, A. virginianum, wild comfrey, grows in dry open woodland and along forest edges across eastern North America. Plants die back to the rootstock or set seed and die after flowering. The bristly foliage and clinging burs limit its use in tended borders.

Native Range

Andersonglossum spp. is native to North America, ranging across much of the eastern and central United States and into southern Canada, with A. occidentale extending into the western United States and A. boreale reaching northern and boreal regions.

Suggested Uses

Andersonglossum spp. is grown in native-plant gardens, woodland edges, and naturalised dry shade, where the early pale blue flowers draw bees and other small pollinators. The barbed nutlets make it less suited to plantings beside paths or where pets pass.

How to Identify

Identify Andersonglossum spp. by its basal rosette of soft-hairy oblong leaves and erect stem topped with curving one-sided racemes of small pale blue flowers. The four barbed nutlets that form after flowering and cling to fur or fabric are characteristic of the genus. Hairy stem leaves that clasp or narrow at the base help separate it from true Cynoglossum spp. and from Hackelia spp..

Appearance

Size & Dimensions

Height1' - 3'4"

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks

Spring Summer

Flowering occurs in late spring to early summer (roughly May-June across much of the range), when the curving racemes open their pale blue to lavender flowers over two to three weeks. Barbed nutlets ripen through summer. Plants flower in their second year or later, after building a rosette the previous season.

Detailed Descriptions

Flower Description

pale blue to lavender

Foliage Description

green

Growing Conditions

Sun Requirements

SunPartial Shade SunFull Sun

• 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 - 7.5(Neutral)

357912

Soil Types

loam sand rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Across the genus, Andersonglossum spp. grows in dry to moderately moist, well-drained soils in light shade to partial sun, typical of open woodland and woodland edges. Plants tolerate poor, rocky, or sandy ground and need little supplemental water once the rosette is established. Self-sown seed, spread by the clinging burs, maintains stands from year to year, since individual plants are short-lived. The soft hairs on leaves and stems can irritate sensitive skin. Rich, heavily fertilised soil produces lax growth, so lean conditions suit the genus. Plants form a deep taproot and re-establish slowly after transplanting.

Pruning

No formal pruning is needed. Spent flowering stems can be cut back after the barbed nutlets form to limit self-seeding, or left standing for the seed to disperse naturally. Removing faded rosette leaves keeps plants tidy.