Taxonomic Revision of the Ant-Acacias (Fabaceae, Mimosoideae, Acacia, Series Gummiferae) of the New World Author David S. Seigler Author John E. Ebinger text Annals of the Missouri Botanical Garden 1995 82 117 138 http://www.jstor.org/stable/2399983 journal article antacacia2399983 http://dx.doi.org/10.2307/2399983 KEY TO THE SPECIES OF ANT ACACIAS la. Petiolar glands usually saddle-shaped or canoe-shaped, or long and narrow, lower than the petiolar groove and nearly as long as the petiole. 1b. Petiolar glands dome-shaped, volcano-shaped, or columnar, rarely absent. 2a. Petiolar glands long and narrow, lower than the petiolar grooves and nearly as long as the petiole ...... ...................................... 4. A. cookii 2 b. Petiolar glands saddle-shaped or canoe-shaped. 3a. Spines with two longitudinal flanges; leaflets more than 10 mm (usually 12-18 mm) long ...... ...................................... 10. A. mayana 3b. Spines lacking longitudinal flanges; leaflets less than 10 mm long. 4a. Leaflets with 2-3 veins from the base, lateral veins obvious; inflorescence more than 3 times longer than wide.......5. A. cornigera 4b. Leaflets with one vein from the base, lateral veins not obvious; inflorescence subglobose, less than 2 times longer than wide ................................................................................................................ 13. A. sphaerocephala 5a. Inflorescence cylindrical, more than 5 times longer than wide. 5b. Inflorescence globose, never more than 2 times longer than wide. 6a. Leaflets with one vein from the base, lateral veins not obvious; enlarged stipular spines flattened at the base........8. A. hindsii 6b. Leaflets with 2-5 veins from the base, lateral veins obvious; enlarged stipular spines terete or oval in cross section. 7a. Petiolar glands usually solitary; rachis glands scattered along leaf rachis........................6. A. gentlei 7b. Petiolar glands 3-5; rachis glands absent..................................................................................................3. A. collinsii 8a. Leaflets more than 1.8 mm wide, with 2-3 veins from the base, lateral veins obvious .... 1. A. allenii 8b. Leaflets mostly less than 1.8 mm wide, with one vein from the base, lateral veins not obvious. 9a. Adaxial surface of the petiole flattened (on well-developed leaves) with numerous petiolar glands (6-30) present on the flattened surface..............................................................................11. A. melanoceras 9b. Adaxial surface of the petiole grooved with fewer than 13 petiolar glands present in the groove. 10a. Stipular spines asymmetrical, commonly curved around the stem, pubescent with yellowish hairs ..................................................................................................................................... 9. A. janzenii 10b. Stipular spines symmetrical, glabrous to puberulent. 11a. Rachis glands cylindrical and narrowing toward the base; most stipular spines not enlarged, those that are usually not inhabited by acacia-ants........12. A. ruddiae 11b. Rachis glands narrowly volcano-shaped, or columnar and not narrowing toward the base; most stipular spines enlarged and inhabited by acacia-ants. 12a. Petiolar and rachis glands columnar; inflorescences in clusters of 10-40; fruit margins ridged.................................................................. 2. A. chiapensis 12b. Petiolar and rachis glands narrowly volcano-shaped; inflorescences in clusters of 4-8; fruit margins not ridged.................................................7. A. globulifera