Calliandra eriophylla Benth.

Authors

Rupert C. Barneby

Authority

Barneby, Rupert C. 1998. Silk tree, guanacaste, monkey's earring: A generic system for the synandrous Mimosaceae of the Americas. Part III. Calliandra. Mem. New York Bot. Gard. 74: 1-223.

Family

Mimosaceae

Scientific Name

Calliandra eriophylla Benth.

Type

Typus infra sub var. eriophylla indicatur.

Description

Species Description - Microphyll xeromorphic shrubs variable in stature and (seasonally) in display of foliage, in desert and desert-grassland commonly 1.5-6 dm, depressed and intricately stiffly branched, but in sheltered places or deeper soils attaining 12 dm and more erect, occasionally on the Mexican Plateau fruticose to 2 m tall but the trunks scarcely 1 cm diam, the terete, annoti- nous and older stems fuscous or blanched in age, the young branchlets whitish-puberulent, the lf-axes, dorsal face of lfts, peduncles and fl-buds finely strigulose or pilosulous with shining, straight and forwardly subappressed, or spreading-ascending and then sometimes wavy, hairs to 0.2-0.7 mm, the mature lfts almost always glabrous on upper face, the few-fld capitula borne mostly solitary on short brachyblasts but sometimes also axillary to primary lvs of new branchlets; phyllotaxy distichous. Stipules linear-lanceolate or narrowly subulate, those associated with primary lvs l-4(-4.8) x 0.15-0.5 mm, all smooth dorsally or faintly l(-3)-nerved, deciduous. Lf-formula (i-)ii-iv/ 8-17(-20), the pinnae of at least some primary lvs 2 or more pairs, but those of many brachyblast-lvs geminate; lf-stks of primary lvs 7-30 mm, the petiole 2-9.5 mm, at middle 0.2-0.55 mm diam, the interpinnal segments a little longer or shorter; pinnae scarcely graduated, the rachis of longer ones (6.5-) 8-20 mm, the longer interfoliolar segments (0.6-) 0.7-1.8(-2) mm; lft-pulvinules 0.1-0.25 x 0.15-0.25 mm, not wrinkled; lfts decrescent only at very ends of rachis, otherwise subequiform, the blades narrowly ovate-oblong, broad-linear or linear from bluntly auriculate base, deltately apiculate or obtuse, the larger ones 2.5-6(-8) x (0.6-)0.7-1.8(-2.1) mm, (2.3-)2.5- 5.2(-5.7) times as long as wide; midrib of lfts a trifle forwardly displaced from mid-blade, straight or almost so, simple or sometimes faintly 2-3-branched on each side, rarely accompanied by 1-2 short and faint incurved primary posterior venules, the venation immersed on upper face of blade, sometimes on both faces. Peduncles subfiliform 3-16(-24, seldom over 12) mm, ebracteate; capitula (2-)3-7-fld, the fls homomorphic, the receptacle scarcely more than 1 mm diam; bracts 0.6-1.1 mm, tardily deciduous; pedicels 0, or very short, then often visible only in section, at most 0.4-0.7 mm; perianth 5-merous, the submembranous calyx 5-nerved, the corolla reddish- pink or carmine, both usually silky-pilosulous but sometimes thinly so and occasionally glabrous; calyx shallowly campanulate or patelliform 0.6-2.1 (-2.4) mm, the teeth depressed-ovate or -deltate 0.3-0.6 mm, ± incurved; corolla (2.4-)3.4-5.5 mm, the lobes (1.5-)1.8-2.4(-2.8) mm, commonly recurved in age; androecium (21-)24-34-merous, (13-)16-24(-27) mm, the internally thickened tube 1.7-3.2 mm, the stemonozone to 1.2 mm but sometimes obscure, the tassel distally pink or crimson, an intrastaminal nectary in most fls 0.4-1 mm tall; ovary subsessile, at anthesis glabrous, becoming sericeous after fertilization. Pods erect, 4—10 x 0.5-0.75(-l) cm, the sutural ribs in dorsal view 1.6-2.4 mm wide, the recessed valves stiffly papery, bullate over 3-8 seeds, nearly always densely pilosulous with either spreading or retrorse hairs, rarely densely minutely pilosulous, the ribs either equally pubescent or glabrescent; seeds 4.8-6 x 3-4.6 mm, oblong-ellisoid to pyriform or plumply discoid, the hard smooth testa light brown, nearly always mottled, the pleurogram slenderly engraved. According to Benson and Darrow (1954: l.c.) the plants furnish excellent browse and can regenerate by suckering.

Distribution and Ecology - Calliandra eriophylla, the one species of its genus common in the northern Sonoran and Chihuahuan deserts, with disjunct populations further south, is difficult to characterize neatly, because of marked seasonal dimorphism of the foliage. Plants bearing many, relatively large, primary leaves, in vigorous spring growth, are deceptively different from those flowering from brachyblasts after the ephemeral primary leaves have been shed. The species is closely akin to the vicariant, but less widely dispersed C. conferta, C. californica, and C. biflora, which see for commentary on differential characters.

Variation - Despite distracting random variation in leaf-formula and size of flowers, only one morphologically weak variety is taxonomically recognizable. With misgiving I refer to var. eriophylla two collections from Sonora (VanDevender 92-227; H. S. Gentry 1281, both NY) that differ in relatively ample leaves (lf-stks to 3-5.5 cm, pinna-rachises to 2-3.5 cm) and more numerous (28-38, not 16-27) filaments. The specimens, both gathered in February, are in poor condition and may represent a distinct taxon.

Relationships - The species is closely akin to the vicariant, but less widely dispersed C. conferta, C. californica, and C. biflora, which see for commentary on differential characters.

Distribution

Arizona United States of America North America| Baja California Mexico North America| California United States of America North America| Sonora Mexico North America| New Mexico United States of America North America| Chihuahua Mexico North America|