Johnstonella angustifolia (narrow-leaved cryptantha)

Johnstonella spp.

Arid southwestern North America and Mexico; parts of arid South America

Native to North America

Overview

Johnstonella spp. is a genus of small, bristly annual herbs in the borage family, Boraginaceae, recently segregated from the large genus Cryptantha spp.. The plants are low, often greyish and rough-hairy, mostly 2 to 12 inches (5 to 30 cm) tall, branching from the base. Tiny white flowers, each with five rounded lobes and a small yellow or white centre, are clustered in coiled sprays that straighten as the flowers open, in the manner of forget-me-nots. The flowers are followed by small, hard nutlets whose shape and surface markings are the main features botanists use to tell the species apart and to separate Johnstonella spp. from Cryptantha spp.. The genus grows in deserts, dry slopes, sandy washes, and open arid ground, mainly in southwestern North America and Mexico, with some species in arid South America. As desert annuals, the plants germinate after rain, flower quickly, set seed, and die within a season, so they are present above ground only briefly. The small flowers make a limited display and are of more botanical than ornamental interest.

Native Range

Johnstonella spp. is native mainly to the arid regions of southwestern North America and Mexico, with some species in dry parts of South America. The plants grow in deserts, sandy washes, and open arid ground.

Suggested Uses

Johnstonella spp. is grown mainly in native desert and restoration plantings and in collections of arid-land flora. The plants contribute to seasonal desert wildflower displays after rain. They carry more value for habitat and botanical study than for garden show.

How to Identify

Plants are small, rough-hairy, greyish annuals branching from the base, with narrow leaves. Tiny white five-lobed flowers open in coiled sprays that uncurl as they mature, like miniature forget-me-nots. The hard nutlets, with their particular shape and surface pattern, are needed to confirm Johnstonella spp. and to tell it from Cryptantha spp..

Appearance

Size & Dimensions

Height2" - 1'

Width/Spread2" - 10"

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~4 weeks

Spring

Flowering occurs in spring after winter and spring rains, roughly March to May, with the timing and abundance varying from year to year with rainfall. The flowers are small and white with a yellow or white throat. The brief desert bloom draws small bees and other insects.

Detailed Descriptions

Foliage Description

grey-green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 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 Range6.5 - 8.0(Alkaline)

357912

Soil Types

sand rocky

Drainagewell drained

Water & Climate

Water Needs

Very Low

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Johnstonella spp. grows in full sun in sandy, gravelly, sharply drained desert soils and needs little water beyond seasonal rainfall. The plants are warm-climate annuals adapted to arid ground and complete their life cycle in a single season. Germination follows autumn or winter rain, and growth depends heavily on the amount and timing of that rain. The plants are not frost-hardy and are rarely cultivated, growing instead as part of natural desert annual displays. Propagation, where attempted, is by seed sown in autumn in a free-draining mix.

Pruning

No pruning is needed, as the plants are short-lived annuals that die after setting seed. Spent plants can be cleared once seed has dropped. Leaving the dried plants in place allows seed to fall for the next season.