Calliandra tergemina

Title

Calliandra tergemina

Authors

Rupert C. Barneby

Scientific Name

Calliandra tergemina (L.) Benth.

Description

76.  Calliandra tergemina (Linnaeus) Bentham, London J. Bot. 3: 96. 1844, the epithet transferred from Inga tergemina Willdenow, which is based on Mimosa tergemina Linnaeus. — Typus infra sub var. tergemina indicatur.

Macrophyllidious shrubs and slender trees flowering when (0.6-)1.5-6(-10) m tall, with smooth pallid annotinous and older branchlets, the epidermis splitting lengthwise and exfoliating in papery strips, the new growth often glabrous except for ventrally puberulent lf-axes and puberulent peduncles but the whole plant at times variously puberulent or pilosulous, the membranous or (in sunny sites) subcoriaceous lfts bicolored, dull green above, paler beneath, the slenderly pedunculate capitula borne mostly solitary on short, thatched brachyblasts axillary to coeval lvs of pliant long-shoots, or some directly from primary lf-axils; phyllotaxy distichous. Stipules subtending primary lvs narrowly triangular or lanceolate 1—4.5(—5.5) mm, striately 4—9(-13)-nerved, deciduous, those of short-shoots commonly smaller and more persistent, when persistent becoming blanched and nerveless externally. Lf-formula i/1 (-2, but only in random, exceptionally in nearly all lvs); petioles (2-)5-28(-34) x 0.3-0.85(-1.1) mm, the terminal appendage either setiform or lanceolate; rachis of longer pinnae (2.5-)3.5-24(-34) mm, the proximal lft(s) inserted 1-4.5(-6) mm from base; lft-pulvinules 0.3-1.1 x 0.3-1.1 mm, cross-wrinkled, sometimes obscurely so; lfts obliquely obovate, semiobovate, or asymmetrically elliptic-(ob)lanceolate from shallowly semicordate base, either obtuse-mucronulate, or deltately subacute, or shallowly emarginate-mucronulate at the rounded or very shortly bluntly acuminate apex, the distal pair (1.3—)1.6—7.5(—8) x (0.5-)0.6-3 cm, exceptionally 8-12 x 3-6 mm, (1.4-)1.8-3.4(-3.8) times as long as wide; venation usually palmate-pinnate, the inner of 2-3 posterior primary nerves incurved-ascending at least to and usually well beyond mid-blade, the secondary and reticular venulation variably prominulous or subimmersed, in microphyll forms rarely 1-nerved. Peduncles (5-)11-40 x 0.3-0.7 mm, either ebracteate or bracteate above (rarely below) middle; capitula (8—)12—21(—26)-fld, the receptacle 1-3 mm; bracts commonly triangular-subulate or linear-lanceolate 0.7-2 mm, exceptionally setiform to 3 mm or deltate 0.4 mm, 1-3-nerved, persistent; fls potentially, in fact almost always, dimorphic, one or more (sub)terminal ones fertile, with broader calyx, a dilated, further exserted staminal tube, and an intrastaminal nectary, the perianth of all fls either greenish, or whitish, or pink to vivid carmine, either 4- or 5-merous, usually glabrous but randomly stigulose or pilosulous, the calyx-tube alone, or the corolla-tube also (but not the lobes) prominently striate; PERIPHERAL FLS: pedicel 0-0.8 mm; calyx campanulate 0.6-3.6(-4) x 0.4-1.4(-l.5) mm, the teeth minute obtuse to subulate acute, 0.1-0.9(-l) mm; corolla (4-)4.3-9(exceptionally to 10, 12) mm, the lobes 0.7-2 mm; androecium (8-, 10-)12-28-merous (in Lara, Venezuela, to 42-merous), the stemonozone 1 mm or less, the tube 4—7(exceptionally -10) mm, the tassel either red- carmine throughout, or pallid proximally and pink- tipped, or white-ochroleucous throughout, the filaments sometimes united beyond the tube into fascicles of varying number; ovary (mostly sterile) glabrous at anthesis; disc 0. Pods plagio- or geotropic (not stiffly erect), in broad profile narrowly oblanceolate tapering downward into a stipelike base (4.5-)5.5-15 x 0.6-1.4 cm, glabrous or rarely finely pilosulous, when well fertilized 5-9-seeded; seeds plumply compressed-ellipsoid, in broad view 7-11 x 3.5-5.5 mm, the testa either smooth or crumpled, castaneous often dark- speckled, either pleurogrammic or not, the pleurogram when present narrowly U-shaped.

As defined by the foregoing description, C. tergemina is a variable species of wide dispersal, polymorphic in indumentum, amplitude of leaflets, depth of calyx, color of the stamens, and in occurrence of a pleurogram on the seed coat. At the time that Bentham (1875: 536, sequ) published his summary account of Calliandra, comparatively few collections of C. tergemina and its relatives were accessible. From this biased evidence a glabrous Antillian C. tergemina characterized by a tiny calyx (±1 mm or less), and continental larger-leaved C. emarginata (Guerrero), C. seemanni (Panama) and C. canescens (Veracruz), the last three collectively different in longer calyces and C. canescens yet further in pubescent foliage, seemed plausibly distinct taxa. It is now apparent that the formulae known to Bentham amounted to a random sample of character-states that exist in Mexico and Central America, for many another syndrome of pubescence, leaf-size, leaf-texture (and prominence of venulation), leaflet-outline, length (absolute and proportional) of corolla and stamens has been discovered since. Those known to Britton and Rose in 1928 were either maintained or described as species of Anneslia (ser. Tergeminae,#4-18, incl.). This classification was rejected by Standley and Steyermark (1946: 22, sub C. emarginata) as unrealistic. Standley and Steyermark recognized in the flora of Guatemala only two species in this complex, the glabrous C. emarginata, and C. mexicana, different solely in leaflets at least dorsally pilose, each equally variable in other features and representing probably only one species. McVaugh (1987: 155) described for Flora Novo-Galiciana a glabrate form of C. emarginata growing with an otherwise uniformly pubescent population. Development of indumentum, which sometimes extends to the calyx and perianth, is visually arresting, but has no practical taxonomic application. Equally striking is the range of variation in size and outline of leaflets, which tend to be proportionately broader and more obtuse as they increase in length. But the variation is continuous; moreover an occasional vigorous shoot with ample leaflets arises from a small-leaved parent branch. A like pattern of continuous variation devalues color of the perianth (white, greenish, pink, carmine) and androecium, which varies from white through particolored (white/carmine) to carmine throughout, as a useful taxonomic character. Texture of leaflets is modified by age, season, and microhabitat. The small calyx characteristic of C. tergemina as represented on the Lesser Antilles and coastal northeastern Venezuela coincides with a striate corolla tube; but in west-central Caribbean Venezuela the calyx becomes insensibly deeper and the venulation of the corolla by degrees less distinct, thereby passing into forms outwardly indistinguishable from Central American examples of C. emarginata. On the other hand, Pittier 8822 (NY) from near Valencia, Carabobo has the longer calyx of emarginata combined with the striate tube of typical tergemina. In fact C. tergemina, by historic accident the first to be named, is nothing more than a peripheral expression of a specific type widely dispersed around the western Caribbean and northward. More difficult to compress into one species is variation in the seed-coat, which has no pleurogram in the Antilles, but is without exception pleurogrammic in Mexico. However, the Panamanian type of C. seemannii has the relatively deep calyx of C. emarginata combined with the plain testa of typical C. tergemina. The alternative to a conservative taxonomy, already adopted in part by Standley and McVaugh, is an intricate Hasslerian proliferation of names based on particular specimens.

Provisionally included in my concept of var. emarginata is a series of relatively microphyll races or forms in which the larger distal leaflets, even of primary leaves, are less than 2 cm or even less than 1.5 cm long. Their biological status requires further study, but is is likely that they are not a monophyletic group but parallel derivatives of var. emarginata s.lat., different one from the next in details of pubescence, venation, and color of perianth and androecium. The following list of specimens indicates the scattered occurrence of the microphyll populations within the range of typical emarginata: MEXICO. Sinaloa, Mazatlán, Rose 14155 (NY); Guerrero: San Marcos, Macqueen 407 (K); Veracruz: mun. Actopán, R. Acosta P. 534 (NY); Oaxaca: Niltepec, R. M. King 1805 (NY). EL SALVADOR. Ahuachapan, C. E. Hughes 1235 (NY). BELIZE. El Cayo distr., T. B. Croat 23531 (NY, one leaf on incipient branchlet to 30 x 13 mm).