The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

kidneywood

spiny kidneywood

Habit Shrubs or trees, unarmed, mostly glandular-punctate throughout newer growth and reproductive material. Shrubs, to 1 m. Leaves (0.5–)1–2.5(–3) cm; leaflets (5 or)7–15(or 17), blades suborbiculate to oblong-ovate, 1–4(–5) mm, surfaces pubescent abaxially, with glands of similar size, glabrous adaxially.
Stems

erect, eglandular or glandular-punctate, brown- to gray-pubescent, often becoming glabrescent.

Leaves

alternate, odd-pinnate, scented when crushed;

stipules present, subulate, relatively small;

petiolate;

leaflets (5 or)7–47[–61], stipels usually present, subulate, blade margins entire, surfaces pubescent abaxially, brown glands sometimes present, glabrous or pubescent adaxially.

Racemes

1–3.5 cm.

Inflorescences

(5–)30–100(–150)-flowered, usually terminal, rarely axillary, racemes (spikelike);

bracts present, early-deciduous to persistent, minute, usually lanceolate;

bracteoles minute or absent.

Flowers

fragrant, not typically papilionaceous;

calyx funnel-shaped, pubescent, lobes 5;

corolla white [yellow-white or pink], sometimes becoming purple, slightly irregular, petals scarcely differentiated, subequal, eglandular, glabrous;

stamens 10, visible, diadelphous, filaments connate ca. 1/2 their lengths;

anthers basifixed;

style bent apically, often with gland at bend or near tip;

stigma capitate.

calyx tube 2–3 mm, lobes acute to acuminate, 0.5–0.9 mm;

corolla white, turning purple, 4–6(–7.5) mm;

style eglandular.

Fruits

legumes, subsessile to short-stalked, laterally compressed, ovoid-ellipsoid, oblong, or oblong-lanceolate, indehiscent, glabrous.

Legumes

ascending, straight, ovoid-ellipsoid, 4.5–6 × 2.5–3 mm, length less than or equal to 2 times width, not flattened.

Seeds

1(or 2), obovoid, oblanceolate, or oblong-subreniform to falcate-ellipsoid.

completely filling legume, slightly compressed, obovoid, edges blunt.

x

= 10.

2n

= 20.

Eysenhardtia

Eysenhardtia spinosa

Phenology Flowering Jul–Oct.
Habitat Dry, semi-desert grassland and shrubland.
Elevation 1200–1700[–2000] m. (3900–5600[–6600] ft.)
Distribution
from USDA
sw United States; sc United States; Mexico; Central America (El Salvador, Guatemala)
[BONAP county map]
from FNA
TX; Mexico (Chihuahua, Durango)
[BONAP county map]
Discussion

Species 10–15 (3 in the flora).

Eysenhardtia is a complicated genus with unclear species boundaries, especially in Mexico. It is closely related to Amorpha, Apoplanesia, Errazurizia, and Parryella, all members of the papilionoid tribe Amorpheae (M. McMahon and L. Hufford 2004).

The Mexican Eysenhardtia polystachya is reputed to be a New World source of lignum nephriticum, which was used to treat kidney ailments (J. M. Lang and D. Isely 1982). Wood chips from this plant, placed in water, produce a solution that fluoresces blue in bright light. The tropical Asian Pterocarpus indicus Willdenow also has been a source of lignum nephriticum. The chemical properties of these fluorescent solutions were described by M. Muyskens (2006).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Eysenhardtia spinosa can appear spiny due to the persistent, dead inflorescence rachises that are short and erect. By far the rarest species of the genus in the flora area, it has been collected in Presidio County.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Shrubs, to 1 m; styles eglandular; racemes 1–3.5 cm; legumes ascending, straight, ovoid-ellipsoid, lengths less than or equal to 2 times widths, not flattened; seeds completely filling fruit, slightly compressed, edges blunt; leaves (0.5–)1–2.5(–3) cm, leaflets (5 or)7–15(or 17), blades 1–4(–5) mm, abaxial surfaces with glands of similar size; w Texas.
E. spinosa
1. Shrubs or trees, 1.5–5 m; styles with glands near tip; racemes 3–11(–16) cm; legumes ascending or reflexed, straight or falcate, oblong or oblong-lanceoloid, lengths more than or equal to 3 times widths, flattened throughout or near base; seeds filling 1/2 or 2/3 of fruit, slightly or strongly compressed, edges blunt or sharp; leaves (1–)2–10(–14) cm, leaflets (7–)13–35(–47), blades 3–20 mm, abaxial surfaces with some glands much larger than others; Arizona, New Mexico, Texas.
→ 2
2. Leaflet blades with largest abaxial glands along midvein and margins; legumes ascending, flattened near base; seeds filling ca. 2/3 of fruit, slightly compressed, edges blunt; Texas.
E. texana
2. Leaflet blades with largest abaxial glands randomly scattered; legumes reflexed, entire fruit appearing flattened; seeds filling ca. 1/2 of fruit, strongly compressed, edges sharp; Arizona, New Mexico.
E. orthocarpa
Source FNA vol. 11. Author: Douglas H. Goldman. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae Fabaceae > subfam. Faboideae > Eysenhardtia
Sibling taxa
E. orthocarpa, E. texana
Subordinate taxa
E. orthocarpa, E. spinosa, E. texana
Name authority Kunth in A. von Humboldt et al.: Nov. Gen. Sp. 6(fol.): 382; 6(qto.): 489, plate 592. (1824) — name conserved Engelmann: Boston J. Nat. Hist. 6: 174. (1850)
Web links