Mimosa grahamii A. Gray
Fabaceae (Pea family)
Synonym(s): Mimosa grahamii var. lemmonii
USDA Symbol: MIGR2
"Spreading or decumbent shrub, 45.0 to 80.0 cm in height at matruity; the branches glabrous to pubescent, with spines usually somewhat hooked, but some may be straight; leaves 5.0 to 10.0 cm in length, the rachis prickly and with 4 to 8 pairs of pinnae, leaflets 8 to 15 pairs per pinna and 4.0 to 6.0 mm long; flowers white to pink, borne in globose axillary heads; fruits (legumes) linear, flat, not strongly constricted between the seeds, 2.0 to 3.5 cm in length, the margins entire or prickly; the leaves, flowers and fruits ranging from glabrous to pubescent." (webref: 50). "Low-growing, armed shrub, erect to spreading, to 80 cm tall thorns opposite, cat-claw shaped, thorns opposite, the stems striated, tan to brown in color. Leaves: Pinnately compound leaves, 5-10 cm long including the petiole, leaflets not crowded, 3-6 mm long, 8-15 pairs per pinna, oblong, distinctly veined. Flowers: Flowers small, sessile, white to pink, in many flowered globose heads or spikes, these flowers have long-exserted, colorful stamens, which appear to be the flower, and give the flower the appearance of a fluffy spike or ball. Fruits: Pods with armed margins, the pods often somewhat contorted, with slight restrictions between the pods, glabrous or slightly pubescent. Ecology: Found from 4,000-6,000 feet (1219-1829 m); flowering April-August." (webref: 23). "Shrubs 6-20 dm, armed at most nodes with a pair of straight, widely ascending hornlike infrastipular aculei 3-10 mm and randomly on intemodes with a solitary recurved infrapetiolar one, the young stems, foliage, and usually the aculeate leaf axes pilosulous with soft erect-ascending hairs 0.2-0.4 mm, exceptionally subglabrous, the pale green concolorous leaflets either facially glabrous ciliolate or pilosulous on both faces, the globose capitula axillary to coeval leaves on hornotinous branchlets." (bibref: 1811).
From the Image Gallery
Plant CharacteristicsDuration: Perennial
Leaf Arrangement: Alternate
Leaf Complexity: Bipinnate
Size Notes: "To 80 cm tall." (webref: 23).
Leaf: "Leaves 5.0 to 10.0 cm in length, the rachis prickly and with 4 to 8 pairs of pinnae, leaflets 8 to 15 pairs per pinna and 4.0 to 6.0 mm long." (webref: 50). "Pinnately compound leaves, 5-10 cm long including the petiole, leaflets not crowded, 3-6 mm long, 8-15 pairs per pinna, oblong, distinctly veined." (webref: 23). "Stipules papery brownish 2-6 (-12) mm, usually ligulate obtuse, incurved and 2-3-nerved distally, or some lower ones ovate, rarely the longer ones attenuate subsetiform; leaf-formula v-ix(-xii)/(7-) 9-17 (-20), the leaf stalks (3-) 3.5-11 cm, the ventral sulcus continuous (spicules 0), the pinna-pairs seldom exactly opposite; rachis of longer pinnae 12-33 mm; leaflets lance- or ovate-oblong, obtuse or acute apiculate, the larger ones (2.5-) 3-6 (-6.5) x 1-2.1 mm, 2.2-3.5 (-3.8) times as long as wide, all veinless ventrally, dorsally 2-3-nerved from pulvinule, the moderately displaced midrib pinnately 2-3-branched on each side, the inner posterior nerve brochidodrome beyond mid-blade, the venulation becoming prominulous and pallid in age." (bibref: 1811).
Flower: "Flowers white to pink, borne in globose axillary heads." (webref: 50). "Flowers small, sessile, white to pink, in many flowered globose heads or spikes, these flowers have long-exserted, colorful stamens, which appear to be the flower, and give the flower the appearance of a fluffy spike or ball." (webref: 23). "Peduncles solitary and 2-3-nate, (1-) 1.5-3.5 cm; capitula without filaments (6-) 7-9.5 mm diam., moriform, the flower buds either glabrous or pilosulous, the clavate receptacle 1.5-4 mm long; flowers 5-merous 10-androus, sessile or almost so, all bisexual; calyx narrowly campanulate (1.2-) 1.5-2.2 mm, the minute teeth 0.1-0.2 mm, sometimes tipped with a reddish granule, the orifice otherwise either glabrous or ciliolate; corolla subtubular (3-) 3.3-4.8 mm, the almost erect lobes 0.8-1.2 mm, either glabrous or thinly pilosulous extemally; filaments whitish, sometimes fading cream-color, united at very base to corolla, exserted 4-6 mm." (bibref: 1811).
Fruit: "Fruits (legumes) linear, flat, not strongly constricted between the seeds, 2.0 to 3.5 cm in length." (webref: 50). "Pods with armed margins, the pods often somewhat contorted, with slight restrictions between the pods, glabrous or slightly pubescent." (webref: 23). "Pods 1-7 per capitulum sessile or contracted at base into a stipe to 2 mm, in profile narrowly oblong to linear, straight or gently decurved, (15-) 20-57 x 4.5-7 mm, 3-8-seeded, the stout, straight or shallowly undulate replum randomly armed with few distant erect aculei 0.5-2.5 mm, the stiffly papery, dark brown, vestigially puberulent but often densely granular valves low-umbonate over seeds, when ripe falling from replum in one piece." (bibref: 1811).
Bloom InformationBloom Color: White , Pink
Bloom Time: Apr , May , Jun , Jul , Aug
DistributionUSA: AZ , NM
Native Distribution: "This uncommon species is confined to dry slopes and mesas in the southwest corner of New Mexico at 1,370-1,830 m (4,500-6,000 ft) in elevation. It is common in Arizona and Mexico where several varieties have been described." (webref: 50). "Scattered along the eastern foothills and lower slopes of Sierra. Madre Occidental from Durango north through Chihuahua to northeastern Sonora, thence north in United States to southeastern. Arizona and southwestern New Mexico (Isely, 1973, map 31)." (bibref: 1811).
Native Habitat: Copy from Plants of Arizona. "Desert grassland, rocky slopes, road cuts." (reslit: 2886). "4,000-6,000 ft (1219-1829 m)" (webref: 23). "In open stony places and on rocky stream banks, in oak woodland and desert grassland, 1150-1850 m." (bibref: 1811).
BibliographyBibref 18 - Feasting Free on Wild Edibles (2002) Angier, B.
Bibref 811 - Tallgrass prairie wildflowers : a field guide to the wildflowers, grasses, and woody vines of the tallgrass prairie (1995) Ladd, D. M. ; F. Oberle
Search More Titles in Bibliography
Web ReferenceWebref 50 - New Mexico Rare Plants (2020) New Mexico Rare Plant Technical Council
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter
Research LiteratureReslit 2886 - Legumes of the United States. IV. Mimosa (1971) Duane Isely
This information was provided by the Florida WIldflower Foundation.
Search More Titles in Research Literature
Additional resourcesUSDA: Find Mimosa grahamii in USDA Plants
FNA: Find Mimosa grahamii in the Flora of North America (if available)
Google: Search Google for Mimosa grahamii
MetadataRecord Modified: 2021-03-12
Research By: JAM