Acacia gentlei Stand.

David S. Seigler & John E. Ebinger, 1995, Taxonomic Revision of the Ant-Acacias (Fabaceae, Mimosoideae, Acacia, Series Gummiferae) of the New World, Annals of the Missouri Botanical Garden 82, pp. 117-138: 127

publication ID

http://dx.doi.org/10.2307/2399983

persistent identifier

http://treatment.plazi.org/id/5F193496-3368-12AD-67E7-915A718E61E2

treatment provided by

Jeremy

scientific name

Acacia gentlei Stand.
status

 

6. Acacia gentlei Stand.  , Publ. Field Mus. Nat. Hist., Bot. Ser. 22: 77. 1940. TYPE: Belize. P. Gentle 185 (holotype, F)  .

Small tree to 20 m tall; young twigs dark reddish brown, densely puberulent. Stipular spines dull, red to dark brown, most commonly black, usually lightly puberulent, terete, commonly symmetrical to slightly asymmetrical, U-shaped with an angle of 30 to 60°, suberect to recurved around the stem, 35-80 mm long, 3.5-6 mm thick near the base. Leaves 70-180 mm long; pinnae 5-12 pairs per leaf, 55-90 mm long, 13-20 mm between pinna pairs; rachis grooved, puberulent, a narrow, volcano-shaped gland located on the rachis internodes between each pinna pair; petiole grooved, densely puberulent, 9-20 mm long. Petiolar glands narrowly volcano-shaped, usually laterally compressed, solitary (rarely 2), puberulent, lightly striate, apex 0.6-1.2 mm across, base 2-3 mm long, located near the base to middle of the petiole. Leaflets 20-35 pairs per pinna, glabrous, linear, 7-14 mm long, 1.8-3.1 mm wide, lateral veins obvious, 3-5 veins from the base, apex obtuse to acute, margins ciliate. Inflorescence a densely flowered, cylindrical spike 15-40 mm long, 4-6 mm thick, nearly the same thickness throughout, apex blunt, in racemes on fertile branchlets with usually one (occasionally 2-4) spike at a node in the axil of a reduced leaf; peduncles puberulent, 16-22 mm long, 0.7-1.1 mm thick, nearly the same thickness throughout; involucre located near the middle of the peduncle, puberulent, 4-lobed with 2 lobes longer. Floral bracts peltate, apex circular, puberulent, the stalk less than 1 mm long. Flowers sessile; calyx 5-lobed, puberulent, 0.5-0.8 mm long; corolla 5-lobed, puberulent, yellowish, 1.3-1.8 mm long, twice as long as the calyx. Legumes straight to slightly curved, flattened, 160-300 mm long, 9-14 mm wide, glabrous, longitudinally striate, black to dark brown, dehiscent along both sutures, stipe 10-30 mm long, the apex narrowing to a spikelike beak 10-40 mm long. Flowering January-May.

Distribution. Rainforests, wet successional areas where the vegetation is 15-20 years of age, wet disturbed sites, swamps, and river edge vegetation in the lowlands of Belize, northern Guatemala, and extreme southern Mexico.

Representative specimens. BELIZE. 3-6 mi. S of Belmopan , Dwyer 12544 ( F,  GH,  MO)  ; Southern Hwy., 14 mi. N of Punta Gorda, San Antonio , Gentry 8072 ( MEX,  MO)  ; Maskall , Gentle 1121 ( F,  GH,  MICH,  MO,  NY)  ; Hummingbird Hwy. , Gentle 9078 ( F,  MICH,  MO,  NY)  ; Mountain Pine Ridge, Blancaneaux Lodge , Wiley 457 ( MO)  . GUATEMALA. Alla Verapaz: along Rio Sebol between Sebol and Carrizal, N of Sebol , 200-300 m, Steyermark 45762 ( F)  . Izabal: El Zapotillo, 1 km E El Estor (Lake Izabal) , Janzen 657 ( F,  GH,  MEX,  MICH,  MO,  US)  . El Petén: Uaxactun , Bartlett 12578 ( NY,  TEX,  UC)  . Tikal National Park, Tikal, in ramonal , Ibarra 16 ( LL)  . MEXICO. Chiapas: a 3 km al S de Frontera Corozal, sobre el Rio Usumacinta , 120 m, Martinez S. 11433 ( MEX,  MO,  NY)  . Quintana Roo: a 2 km al N de Estero Franco, carretera Chetumal-La Union , Cabrera & Cabrera 2512 ( MEX,  MO)  . Tabasco: Carretera W-O por El Poblado de Apatzingan, Balancan , 150 m, Calzada 2345 ( F,  MEX,  MO)  .

Acacia gentlei  is a common species in wet sites at lower elevations in Belize, Guatemala, and extreme southeastern Mexico. It is distinguished easily from all other ant-acacias by the combination of its elongate inflorescence, laterally compressed, volcano-shaped glands scattered along the leaf rachis, very thin spines (usually less than 6 mm thick), and relatively large leaflets (7-14 mm long) with obvious secondary veins.

Unlike many of the wet forest ant-acacias, Acacia gentlei  is a common species in areas of human disturbance. It appears as a successional species after logging, and in many parts of its range is found along roadsides. Unlike most wet forest ant-acacias, it has relatively large Beltian bodies (1-2 mm long) on most of the leaflets. Like most of the other ant-acacias, it usually lacks cyanogenic glycosides in the leaflets. Of the specimens examined, only one, Lundell 16903, from Guatemala, was weakly cyanogenic.

MEX

MEX

MICH

MICH

TEX

TEX

Kingdom

Plantae

Phylum

Tracheophyta

Class

Magnoliopsida

Order

Fabales

Family

Fabaceae

Genus

Acacia