Phryma spp.

lopseed

Phrymaceae

Eastern North America and temperate East Asia

Attracts Pollinators

Native to North America

SunPart Shade – Full Shade

WaterMedium

HardinessZones 4–8

Overview

Phryma spp. is a small genus of perennial herbs in the family Phrymaceae, traditionally treated as the single species Phryma leptostachya with North American and East Asian populations sometimes separated as varieties. Plants grow upright on slender four-angled stems 12-36 inches (30-90 cm) tall from a short rhizome. The opposite leaves are ovate, coarsely toothed, and 2-6 inches (5-15 cm) long, tapering to a pointed tip. Small two-lipped flowers, 0.2-0.3 inch (5-8 mm) long and white to pale pink or lavender, are spaced in pairs along slender terminal and axillary spikes. As each flower fades, the developing fruit bends sharply downward and presses flat against the spike, a movement that gives rise to the common name lopseed. The single-seeded fruits are enclosed by the persistent calyx, whose hooked teeth catch on fur and clothing for dispersal. Phryma spp. grows in the shade of deciduous woodlands on moist, humus-rich soils, and spreads slowly into open colonies. It tolerates deep shade but flowers sparsely there, and the thin spikes carry little color, so it is grown mainly as woodland groundcover rather than for floral show.

Native Range

Phryma leptostachya occurs across eastern and central North America and, as eastern Asian populations, in China, Korea, Japan, and the Himalaya. It grows on the floor of moist deciduous and mixed woodlands.

Suggested Uses

Used as a groundcover and filler in shade and woodland gardens, native plant borders, and naturalized plantings beneath deciduous trees. It combines with ferns and other woodland perennials on moist soils.

How to Identify

Identified by opposite, coarsely toothed ovate leaves on square stems and slender spikes bearing paired, small two-lipped flowers. The diagnostic feature appears in fruit: each ripening calyx bends abruptly downward and lies pressed against the spike, tipped with three hooked teeth. This sharply reflexed, appressed fruit separates Phryma spp. from mints and vervains with which it can be confused.

Appearance

Size & Dimensions

Height1' - 3'

Width/Spread1' - 2'

Colors

Flower Colors

Foliage Colors

Bloom Information

Bloom Period

~6 weeks

Summer

Flowering occurs in summer, roughly June through August, with flowers opening a few at a time up the spike. Bloom is sparse and brief on each plant. Fruiting follows quickly, and the reflexed calyces persist into autumn.

Detailed Descriptions

Flower Description

White to pale pink

Foliage Description

Green

Growing Conditions

Sun Requirements

SunPartial Shade SunFull Shade

Requires 1-5 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 Range5.5 - 7.0(Neutral)

357912

Soil Types

loam silt

Drainagemoist

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

1-2 years

Care & Maintenance

Care Guide

Grow Phryma spp. in part to full shade on moist, humus-rich, well-drained soil, matching its woodland origins. It needs consistent moisture during the growing season but tolerates short dry spells once established under a tree canopy. Plants spread slowly by rhizome and self-sow where leaf litter is left undisturbed. No staking or feeding is needed in soils with reasonable organic content. In open, sunny, or dry sites growth is weak and short-lived. Top growth dies back in autumn and reappears in spring.

Pruning

No routine pruning is needed. Let the dead stems collapse over winter and clear them in late winter before new shoots emerge. Hooked fruiting spikes can be removed before they ripen to limit self-seeding.