Name
Vachellia cedilloi (Rico Arce) Seigler & Ebinger, Phytologia 87: 150. 2005.
syn. Acacia cedilloi Rico Arce, Acta Bot. Mex. 26: 7. 1994.
Synonymy and types
Basionym: Acacia x cedilloi L. Rico Arce, Acta Bot. Mex. 26: 7. 1994. - TYPE: MEXICO. QUINTANA ROO: km 6.5 de la carretera Vigia Chico-F. Carrillo Puerto, selva mediana subperennifolia, alt. 8 m, 9 Apr 1986, R. Villanueva 714 (holotype: MEXU: isotypes: CIQRO, XAL).
Formal description
Tree to 3 m tall. Bark not seen. Twigs light brown to light gray, not flexuous, glabrous. Short shoots absent. Leaves alternate, 60-150 mm long. Stipular spines usually light brown to light reddish brown, asymmetrical, terete, curved around the stem, stout and inflated, 20-80 x 4-10 mm near the base, glabrous, many stipular spines not enlarged. Petiole adaxially grooved, 8-18 mm long, glabrous to lightly puberulent; petiolar glands absent. Rachis adaxially grooved, 50-140 mm long, glabrous to lightly puberulent, a sessile, narrowly volcano-shaped to nearly columnar gland usually present between the pinnae of each pinna pair, apex 0.4-0.6 mm across, mostly glabrous and striate. Pinnae 6 to 12 pairs per leaf, 28-60 mm long, 7-14 mm between pinna pairs. Petiolules 0.8-1.6 mm long. Leaflets 12 to 28 pairs per pinna, opposite, 1.1-2.1 mm between leaflets, linear, 4-9 x 1.5-2.5 mm, glabrous, lateral veins not obvious, only one vein from the base, base oblique, margins not ciliate, apex usually obtuse; beltian bodies not seen, but scars are present where they were located. Inflorescence a densely flowered cylindrical spike about 2-3 times longer than wide, that narrows slightly toward the blunt apex, 7-15 x 4-8 mm near the base, solitary or in clusters of 2 in the axil of small spines on short, usually leafless axillary branches to 130 mm long, with up to 15 nodes. Peduncles 4-7 x 1.4-2.2 mm, glabrous. Involucre 5- to 7- lobed, located at the base to lower third of the peduncle, glabrous, persistent. Floral bracts peltate, 0.7-1.1 mm long, apex circular and glabrous, deciduous. Flowers sessile, pale yellow; calyx 5-lobed, 0.9-1.3 mm long, glabrous; corolla 5-lobed, 1.0-1.4 mm long, glabrous, only slightly longer then the calyx; stamen filaments 1.2-1.6 mm long, distinct; ovary glabrous, sessile. Legume dark gray, slightly curved, nearly terete in cross section, not constricted between the seeds, oblong, 50-100 x 10-15 mm, coriaceous, not striate, glabrous, eglandular, indehiscent; stipe to 10 mm long, apex narrowing to a spine-like beak 10-20 mm long. Seeds uniseriate, imbedded in a yellowish pulp, light to reddish brown, ovoid to ellipsoid, slightly flattened, 7-9 x 4-6 mm, smooth; pleurogram oblong to U-shaped 2.1-3.3 mm across. Flowers in January to April. Chromosome number: Not determined.
Distribution
In disturbed thorn -scrub vegetation, near sea level, in western Quintana Roo, particularly in Mpio. de Carrillo Puerto and Mpio. Isla Mujeres.
Additional info
In most respects, however, this taxon is very similar to Vachellia cornigera, which also is found in this region. On Vachellia cedilloi, like V. cornigera, the leaves have relatively few pinna pairs (6 to 12). The leaflets are nearly as large as those of V. cornigera, but lack the obvious secondary veins of that species. The inflorescences and fertile branches of V. cedilloi are exact, though miniature copies of those found in V. cornigera. The inflorescences are smaller than those of V. cornigera, being about half the average size, they are cylindrical and narrow toward the apex, whereas the flowers are nearly identical and the same size as those of V. cornigera. The inflorescences are solitary or in clusters of 2 in the axil of small spines on short, usually leafless axillary branches, also nearly identical to those of V. cornigera. It is likely that V. cedilloi represents a hybrid between V. cornigera and V. globulifera. The status of this taxon must await field studies.
Rico-Arce (1994) considered Vachellia cedilloi to be closely related to V. globulifera which it resembles in some of its vegetative characteristics, particularly the laterally compressed volcano-shaped glands found on the rachis between the pinnae of each pinna pair. These glands are in most respects like those found in V. globulifera, except they are usually glabrous, whereas those of V. globulifera are densely puberulent. Vachellia globulifera occurs in the part of Quintana Roo where A. cedilloi is known to occur.
Flowering time
January-April.
Representative specimens
MEXICO:
Quintana Roo:
- Mpio. Carrillo Puerto, Reserva de la Biosfera "Sianka'an", vegetación secúndaria de selva mediana subperennifolia, Km. 8 de Vigia Chico a Carrillo, 25 Jan 1984, R.Duran & I.Olmsted 766 (MO, XAL).