ABCDEFGHIJKLMNOPQRSTUVWXYZ

Name

Vachellia farnesiana (Vachellia farnesiana (Linnaeus) Wight & Arnott var. pinetorum (F. J. Hermann) Seigler & Ebinger, Phytologia 87:157. 2005.
syn. Acacia farnesiana (L.) Willd. subsp. pinetorum (F. J. Herm.) Ebinger & Seigler, Southw. Naturalist 47:90. 2002.

Synonymy and types

Basionym: Acacia pinetorum F. J. Herm., J. Wash. Acad. Sci. 38:237. 1948. - Acacia farnesiana (L.) Willd. subsp. pinetorum (F. J. Herm.) Ebinger & Seigler, Southw. Naturalist 47:90. 2002. - Vachellia farnesiana (Linnaeus) Wight & Arnott var. pinetorum (F. J. Hermann) Seigler & Ebinger, Phytologia 87:157. 2005. - - TYPE: UNITED STATES. FLORIDA: Dade Co., hammocks, Long Key (Everglades), 18-26 Jan 1909, J.K.Small & J.J.Carter 2975; in pinelands, Long Key, 6-7 May 1903, J.K.Small & P.Wilson 1778. (syntypes: NY).

Vachellia insularis J. K. Small, Man. s. e. fl.  655, 1505. 1933. - TYPE: UNITED STATES. FLORIDA:  Monroe Co., pinelands, Big Pine Key, 21 Mar 1915, J.K.Small & C.A.Mosier 6018; pinelands, Big Pine Key, 27 Feb. 1911, J.K.Small, J.J.Carter & G.K.Small 3549 (synthpes: NY). NOTE: Not Acacia insularis A. Richard (1845), an herbaceous legume lacking stipular spines and prickles and is a synonym of Neptunia pubescens Benth. (Bässler 1998).

Vachellia peninsularis J. K. Small, Man. s. e. fl. 654. 1505. 1933. -  TYPE: UNITED STATES. FLORIDA: Dade Co. hammocks, Long Key (Everglades), 18-26 Jan 1909, J.K.Small & J.J.Carter 2975; in pinelands, Long Key, 6-7 May 1903, J.K.Small & P.Wilson 1778 (syntypes: NY). NOTE:  Not Senegalia peninsularis Britton & Rose (1928), a species from Baja California, Mexico that has prickles and lacks stipular spines, nor Acacia peninsularis (Britton & Rose) Standley (1936).

Formal description

Small prostrate to ascending shrub with diffuse branching, usually less than 1.5 m tall.
Bark dark gray to brown, furrowed. Twigs dark reddish brown to dark gray, strongly flexuous, usually glabrous. Short shoots commonly present above the stipular spines, to 10 mm long, covered with acuminate stipules and old leaf bases. Leaves alternate, also commonly clustered on the short shoots, 5-35 mm long. Stipular spines light to dark brown, usually becoming light gray with age, symmetrical, terete, straight, stout, to 35(55) x 1.5 mm near the base, mostly glabrous. Petiole adaxially grooved, 3-7 mm long, usually glabrous; petiolar gland solitary, usually located medially on the petiole, sessile to short stalked, circular to slightly elongated, 0.2-1.0 mm long, apex depressed, glabrous. Rachis adaxially grooved, 10-55 mm long, usually sparsely pubescent with erect hairs, a sessile, circular gland, 0.2-0.4 mm across, between the upper 1 to 2 pinna pairs. Pinnae 2 to 6(7) pairs per leaf, 10-20 mm long, 2-10 mm between pinna pairs. Petiolules 0.5-2.0 mm long. Leaflets 8 to 19 pairs per pinna, opposite, 0.5-2.0 mm between leaflets, oblong, 1.5-3.6 x 0.5-1.4 mm, mostly glabrous, lateral veins usually not obvious, only one vein from the base, base oblique, margins usually not ciliate, apex broadly acute to obtuse. Inflorescence a densely flowered globose head, 6-10 mm across, solitary or in clusters of 2 to 5 on the short shoots. Peduncles 12-36(45) x 0.2-0.7 mm, lightly puberulent. Involucre 4- to 5-lobed, located at the base of the globose head, glabrous to lightly puberulent, persistent. Floral bracts spatulate, 0.8-1.3 mm long, apex puberulent, deciduous. Flowers sessile, bright yellow; calyx 5-lobed, 1.1-1.8 mm long, glabrous or nearly so; corolla 5-lobed, 1.9-2.8 mm long, glabrous or nearly so; stamen filaments 3.5-5.5 mm long, distinct; ovary glabrous to puberulent, on a stipe to 0.2 mm long. Legumes dark brown to black, straight to slightly curved, nearly terete in cross section, not constricted between the seeds, oblong, 30-80 x 9-18 mm, coriaceous, reticulately striate, glabrous, eglandular, indehiscent; stipe to 7 mm long; apex obtuse to acuminate, sometimes beaked. Seeds mostly biseriate, imbedded in a sweet pulp, olive green to dark brown, ovoid to ellipsoid, slightly flattened, 4.2-8.0 x 3.5-5.8 mm, smooth; pleurogram U-shaped to oval, 2.5-4.5 mm across. Flowers throughout the year, but most common from October to May. Chromosome number: Not determined.

Distribution

On moist to dry sites in thickets, open pastures, roadsides, successional fields and other disturbed sites, as well as in open pinelands and hammocks, near sea level in southern Florida, extending north to Citrus County in the central part of the state.

Additional info

Vachellia farnesiana var. pinetorum is relatively common in southern Florida, being found in the keys, disturbed areas along roads in the everglades, and open pinelands in Dade, Monroe, and Lee Counties. The collections from Citrus County may represent introductions, possible from cultivated plants. It appears to be a diminutive, mostly glabrous form of V. farnesiana. In some of its characteristics it has the appearance of this latter subspecies, particularly the petiole gland, and the inflated fruit. It is easily separated from typical V. farnesiana, however, particularly by the smaller leaflets that lack secondary veins, the strongly flexuous twigs, and the overall smaller size of most of the vegetative structures.

Vachellia farnesiana var. pinetorum is not extremely variable.  Rarely the stem, petiole, and rachis are slightly puberulent, and some variation occurs in leaf, leaflet, pinnae, and petiole size. Much of these differences occur because the short shoot leaves are generally smaller than the primary leaves which originate from between the stipular spines on new growth. Short shoots are common on members of the V. farnesiana group, and have been responsible for much of the taxonomic confusion concerning these species. Some of the differences in leaflet size, however, are probably related to environmental conditions. Though most specimens have leaves that rarely exceed 2.5 mm in length, leaflets as long as 3.6 mm long are rarely found. These larger leaflets are common on many of the specimens from Citrus County, Florida.

Many different characteristics have been used to distinguish Vachellia farnesiana var. pinetorum from other member of the Vachellia farnesiana complex (Long and Lakela 1971, Isely 1990). The small, red, deciduous glands are common on the peduncles of V. farnesiana var. pinetorum, but are not always present, and are early deciduous, making it a poor key characteristics. Also, the ratio of the calyx /corolla length has be used, but is too variable to be useful, as are the beaked fruits, which are sometimes found on fruits of typical V. farnesiana.

Many member of the Vachellia farnesiana group commonly give a positive test for cyanide when the leaves are crushes. Vachellia farnesiana var. pinetorum, in contract, is rarely cyanogenic. Of the more that 60 specimens tested only 6 gave a positive test. In all instances, the results were weak after 24 hours.

Flowering time

Throughout the year, but most common from October to May.

Representative specimens

UNITED STATES:

Florida:

Citrus Co.:

Collier Co.:

Dade Co.:

Lee Co.:

Monroe Co.:

Top