Home

Event Calendar

Clinic

Plant Walks

Contact/Mailing List

Kidneywood                                       

Eysenhardtia polystachya (Eysenhardtia orthocarpa)

Palo azul, Bura dulce

 
Leguminosae – Pea family

Description

Kidneywood is a large bush or small tree.  Occasionally it reaches 18 feet in height, but it is usually less.  The outer bark on older sections is gray and fissured and forms in a checkerboard pattern.  Kidneywood’s leaves, which are deciduous in response to drought stresses and low temperatures, are pinnate and are composed of numerous, small leaflets.  Upon closer examination, the small dot-like resin glands are apparent on the undersides of the leaflets, young stems, and flower calyxes.  A resinous odor is noticeable when the foliage is crushed.  The terminal spikes are composed of small, white, delicate flowers that appear in response to warm temperatures and rainfall from early spring to late summer.  They are followed by equally small, linear, clustered green seedpods.  Within each pod is 1 flat seed.

Distribution

Kidneywood is found from 4,000-5,000 feet, from Pima County, Arizona, east to southern Hidalgo County, New Mexico.  Typically, the plant grows on hillsides and canyons of Desert Grasslands and Oak Woodlands.

Chemistry

At least several florescent isoflavones; chalcones: coatline a and b

Medicinal Uses

As the name Kidneywood implies, the tea made from the small branches effects the kidneys and lower urinary tract.  If prone to acidic, overly concentrated urine, associated kidney stones and urinary tract sediment then Kidneywood will be of use.  Because of the plant’s alkalinizing nature, acidic precipitants dissolve back into the urine, thereby reducing pain and urinary tract irritability associated with lithic deposits.  Kidneywood is diuretic and soothing to kidney and urinary tract irritability.  Its mild antimicrobial activity further helps to explain its usefulness to this area of the body.

Indications

Urinary tract gravel

Acidic, overly concentrated urine

Upper and lower urinary tract irritability and pain

Collection and Preparations

After pruning a number of smaller secondary branches from several large plants cut them into small ½-¼ inch sections; the leaves also can be used.  The branch/bark decoction makes a pleasant tasting, slightly astringent tea.

Dosage

Branch/bark decoction: 4-8 ounces 3 times daily

Cautions

The heartwood should not be collected in the United States given the significant impact it would have on our limited but locally available populations.  Moreover, there is not a great medicinal advantage over utilizing these parts over the smaller branches.

Other Uses

Of historical interest is that sixteenth and seventeenth century Western European practitioners and lay people alike employed the plant, then known as Lignum nephriticum, for issues formerly mentioned.  Also during the same period, the chemist Richard Boyle used preparations of the heartwood as an acid - base indicator.  Considered a scientific break through at the time, the process gained a wider acceptance in measuring pH until export of Kidneywood became unstable and fell into neglect.