''Leucophyllum'' (barometer bush or barometerbush) is a genus of

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from tree ...

s in the figwort family,

Scrophulariaceae The Scrophulariaceae are a family of flowering plants, commonly known as the figwort family. The plants are annual and perennial herbs, as well as shrubs. Flowers have bilateral ( zygomorphic) or rarely radial ( actinomorphic) symmetry. The ...

, native to the

southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, ...

and

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Gua ...

. It is sometimes placed in the family Myoporaceae. The dozen-odd species are often called "sages", although they have no relationship to the genus ''

Salvia ''Salvia'' () is the largest genus of plants in the sage family Lamiaceae, with nearly 1000 species of shrubs, herbaceous perennials, and annuals. Within the Lamiaceae, ''Salvia'' is part of the tribe Mentheae within the subfamily Nepetoide ...

''. The solitary axillary flowers are bell- or funnel-shaped, with five lobes and two lips, and colors ranging from white to magenta to purple. The generic name is derived from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

words λευκός (''leukos''), meaning "white," and φυλλον (''phyllos''), meaning "

leaf A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ...

," referring to the trichome-covered foliage. These shrubs are found in

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of ...

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

s and have a high salt tolerance. They have become popular for edge and area plantings in warmer areas and in

xeriscaping Xeriscaping is the process of landscaping, or gardening, that reduces or eliminates the need for irrigation. It is promoted in regions that do not have accessible, plentiful, or reliable supplies of fresh water and has gained acceptance in other ...

; they require minimal water, are easily shaped into

hedge A hedge or hedgerow is a line of closely spaced shrubs and sometimes trees, planted and trained to form a barrier or to mark the boundary of an area, such as between neighbouring properties. Hedges that are used to separate a road from adjoini ...

s, and bloom over their entire surface.

Cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

s of '' L. frutescens'', '' L. candidum, '' L. laevigatum'', '' L. langmaniae'', '' L. pruinosum'', '' L. revolutum'', and '' L. zygophyllum'' have been developed. ''Leucophyllum'' shrubs are legendary for their ability to "forecast" rain, usually blooming several days prior to a rainstorm, apparently in response to humidity. They are sometimes called "

barometer A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis ...

bush" for this reason. It is believed to be a survival trait in the plants' semi-desert habitats.

Selected species

* '' Leucophyllum alejandrae'' G.L. Nesom * '' Leucophyllum ambiguum'' Bonpl. * '' Leucophyllum candidum'' I.M.Johnst. – Brewster County barometer bush * '' Leucophyllum flyrii'' B.L. Turner * '' Leucophyllum frutescens'' ( Berland.) I.M.Johnst. – Texas sage, Texas ranger, silverleaf * '' Leucophyllum hintoniorum'' G.L. Nesom * '' Leucophyllum laevigatum'' Standl. – Chihuahuan sage * '' Leucophyllum langmaniae'' Flyr – Langman's sage, Rio Bravo sage * '' Leucophyllum minus'' A.Gray – Big Bend barometer bush * '' Leucophyllum mojinense'' Henrickson & T. Van Devender * '' Leucophyllum pringlei'' (Greenm.) Standl. * '' Leucophyllum pruinosum'' I.M.Johnst. * '' Leucophyllum revolutum'' Rzed. * '' Leucophyllum ultramonticola'' Flyr * '' Leucophyllum zygophyllum'' I.M.Johnst.

Hybrids

*''Leucophyllum'' × 'Heavenly Cloud' (''L. frutescens'' 'Green Cloud' × ''L. laevigatum'') *''Leucophyllum'' × 'Rain Cloud' (''L. frutescens'' × ''L. minus'')

References

External links

Page on ''L. frutescens'' from Texas Native Plants Database
{{Taxonbar, from=Q2702896 Scrophulariaceae Scrophulariaceae genera Flora of Mexico Flora of the United States Taxa named by Alexander von Humboldt Taxa named by Aimé Bonpland