Calliandra Species Pages

Calliandra haematocephala

Rupert C. Barneby

65.  Calliandra haematocephala Hasskarl, Retzia 1: 216. 1855. — Holotypus infra sub var. haematocephala indicatur.

Macrophyllidious shrubs and treelets 1-5 m tall, diverse in indumentum and in number and size of lfts, glabrous throughout or almost so to densely softly pilosulous (more precisely described under each variety), the hemispherical, prior to anthesis globose capitula arising singly from either imbricately thatched or from variably elongating efoliate, axillary brachyblasts, these commonly immersed in foliage, less often pseudoracemose at tip of currently elongating stems, the capitula notable for densely crowded flowers and usually bright red filaments. Stipules firm, ovate-triangular or lanceolate 3-11 (-13) x 1.4—4.5 (-5) mm, striately venulose when young, becoming thickened, pallid or blanched and externally smooth in age, persistent. Lf-formula i/3—9(—10), the size and number of lfts mutually adjusted; petiole of larger lvs 0.9-4.5(-5) cm, at middle 0.7-2 mm diam, at apex dilated into a pair of homy cupules; rachis of well- developed pinnae 5-11 cm, the longer (distal) interfoliolar segments 0.84.5 cm; lft-pulvinules (0.7-) 1-3 x 0.8-1.5 mm, coarsely cross-wrinkled; lfts variably accrescent distally, the blades inequilaterally elliptic, (ob)ovate-, or lance-elliptic from shallowly semicordate base, obtuse or shortly or obscurely acuminate (the acumen itself obtuse apiculate), the larger ones 2.2—14(—16.5) x 0.7-5.4(-6) cm, 1.9-3.6 times as long as wide; primary nerves from pulvinule 2-3(-4), the gently incurved midrib displaced to divide blade 1:1.4—2.4, ±6-12-branched on its anterior side, the inner posterior nerve nearly as strong, incurved-ascending well beyond mid-blade, the outer 1-2 much shorter, the primary nerves prominulous on both faces, the secondary and reticular nervules also sharply raised but progressively finer. Peduncles 14(-6) cm, either bracteate or not; capitula densely 20-84-fld, the fls contiguous, the clavate receptacle 2—7(!) mm; floral bracts ovate, subulate, or flabellate 0.8-2.4 mm, incurved, ±5-8-nerved, persistent; pedicels either evident or cryptic, (0.3-)0.5-1.2 x 0.6-1.5 mm; perianth glabrous, either 4-merous, or 5-merous, or one cycle 4- and the other 5-merous, the calyx and the corolla-tube striate, the corolla lobes imperceptibly venulose; calyx campanulate (1—) 1.4—3.7(—4) x 1.3-2.9 mm, the orifice often undulately truncate, but sometimes cleft into depressed-ovate or deltate teeth 0.5 mm or less; corolla red or reddish (5—)6.5—11.3(—12) mm, the ovate lobes 1-3.3 mm; androecium (20-)22-40(44)-merous, (22-)30-44 mm, the stemonozone 0.7-1.5 mm, the tube (5.5-)6-11(—13.5) mm, dilated upward into a trumpet ±34 mm diam either a little shorter or to 4(-4.5) mm longer than the corolla, the crimson-scarlet or in cultivation rarely white or pink filaments in one cycle, a few separating from stamen-tube well below orifice, the membranes between filaments produced into curved erose appendages that form a fringe or corona within the orifice; nectary around base of glabrous ovary 0.4—0.9 x 0.5-1 mm. Pods to 5 per peduncle, in broad view 7-13 x 0.8-1.3(-1.65) cm, the sutural ribs in dorsal view 2.5-4 mm wide, the plane recessed, lignescent valves fuscous nigrescent glabrous, transversely venulose; seeds (few seen) in broad view ±8.5-10 x 5.5-7.5 mm, the smooth crustaceous testa brown, minutely speckled or mottled, the pleurogram incomplete.

In seasonally dry subtropical woodland and woodland-savanna transition, 240-800 m., native and locally abundant in the foothills of the Bolivian Andes, between 14°S and 18°S latitude, the dispersal given in greater detail under the varieties; widely dispersed in cultivation. — Powder-puff tree; pompon; bellota; flor de la cruz.

As broadly defined by the foregoing description, C. haematocephala is distinguished among unijugate calliandras not by any one character nor by any combination of characters derived from foliage or indumentum, both of which are inordinately variable, but by the following features of the inflorescence: flowers not less than 25 per capitulum, in bud crowded into a blackberry-like ball; perianth glabrous, the calyx and the corolla-tube striate; filaments monocyclic, several of them separating from the tube below its orifice, where the interfilamental membranes are produced into a corona of inwardly reflexed, pallid erose scales that contrast in color with the blood-red tassel; and a nectarial disc, in bisexual flowers, that embraces the glabrous ovary.

Parts of the C. haematocephala complex have been revised by Cowan (1963) and by Nevling and Elias (1971). Cowan recognized C. haematocephala sens. str., which is widespread in cultivation but not exactly matched by any wild plant, as specifically distinct from C. inaequilatera Rusby, which is known from native populations as well as from cultivars. Nevling and Elias, after analysis of more material, found no substantial differences between these two, and suggested further that C. boliviana Britton, which has precisely the flowers of C. haematocephala but simplified leaves and larger leaflets and is, moreover, sympatric with C. inaequilatera, could well be included, at some infraspecific level, in an expanded C. haematocephala. The new material now available for comparative study confirms this view of C. boliviana. I here include, further, two shadowy taxa: C. fulgens Hooker f., supposedly of Mexican origin but known only from cultivated stock; and C. novaesii Hoehne, described from eastern São Paulo, Brazil, where it has not since been encountered in the wild. My conclusion that C. haematocephala consists of one polymorphic species composed of relatively few native populations and several more or less ambiguous cultivars, all of which are conveniently disposed in two varieties, is expressed in the following key.

References: [Article] 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.