SAPOTACEAE: Sapodilla Family
KEY TO SPECIES OF SIDEROXYLON
1. Leaf blade underside with abundant hairs hiding epidermis, all closely appressed and arranged essentially parallel with main lateral veins ............................... S. alachuense
1. Leaf blade underside glabrous or, if hairy, the hairs not hiding epidermis or, if hiding epidermis, tending to spread in different directions ................................. 2
2. Year 1 twigs abundantly to moderately covered with persistent rusty-red or tawny to brown hairs .................................... S. reclinatum ssp. rufotomentosum
2. Year 1 twigs glabrous or initially bearing light-colored or rarely to rusty hairs ........................................... 3
3. Leaf blade spatulate, widest 1/4 or less from the apex ....................................... S. celastrinum
3. Leaf blade not spatulate, widest at or near middle OR, if spatulate, widest more tha 1/4 from apex .......................... 4
4. Upperside of mature leaf blades (under magnification) with a relatively faint and coarse net-vein system, these veins not raised, usually depressed a little, and, although pale, not bony- cartilaginous in contrast to green of the islets ......................... S. thornei
4. Upperside of mature leaf blades (under magnification) with a fine net-veined system, these veins usually raised above the enclosed islets and bony-cartilaginous in contrast to the green of the islets ........... S. reclinatum