Chloroleucum [sic] guatemalense Britton & Rose ex Record, Trop. Woods 10: 24. 1927. — "Collected by Record & Kuylen near Olanchito [Honduras]. (No. 59; Yale No. 10,005)." — Holotypus, dated 14.II.1927 (fr.), NY!; isotypus, US 1315413!. — Pithecolobium guatemalense (Record) Standley, Publ. Field Mus. Nat. Hist., Bot. Ser. 4: 308. 1929.

Chloroleucon undulatum Britton & Rose, N. Amer. Fl. 23: 37. 1928. — "Type from Sierra de Alamos, Sonora, March 18, 1910, Rose, Standley & Russell 13041." — Holotypus (fr.), NY!; isotypi, F!, US 635861!. — Pithecolobium undulatum (Britton & Rose) H. S. Gentry, Publ. Carnegie Inst. Wash. 527: 121. 1942.

Chloroleucon langlassei Britton & Rose, N. Amer. Fl. 23: 37. 1928. — "Petatlan [on the Pacific coast of Guerrero near 101°15'W], Michoacan or Guerrero, November 23, 1898, E. Langlassé 687a." — Holotypus, US 385639!; isotypi, NY (fragm. + photo)!, P (no. 687)!. — Pithecolobium langlassei (Britton & Rose) Standley, Publ. Field Mus. Nat. Hist., Bot. Ser. 4: 309. 1929.

Foliage, or at least the lf-axes, commonly pilosulous, but in W and S Mexico randomly glabrous; lf- formula ii—v/(6—)7—16, the larger lfts at maturity 7- 16(—17) x 2-6(-10) mm. Pods 14-26 x (0.5-)0.6-1 (—1.5) cm, straight or gently decurved, the sutures shallowly constricted between the subvertically descending seeds, the interseminal isthmi flat.

In short-tree forest, desert chaparral, and semideciduous tropical forest on the coastal plain, ascending on dry hills and along rocky arroyos in the foothills or hilly interior to 600, in Chiapas to 1200 m, widely scattered over the Pacific lowlands of Mexico from S Sonora (Sa. de Alamos) and S Baja California Sur to Chiapas, thence E and SE in scattered stations to centr. Veracruz, Yucatán Peninsula, upland Chiapas, interior Honduras, and N Nicaragua; single records, perhaps adventive, from S Haiti, SE Jamaica, and Virgin Islands (St. Croix). — Map 42. — Fl. most abundantly II-VI, sometimes again VII-X, especially following summer rains. — Palo ebán (Baja California), cucharo, ebano bianco (Sinaloa); borcelano (Guerrero); cachi de toro (Chiapas).

Except that we extend the synonymy to include Ch. guatemalense and Ch. langlassei, our concept of var. leucospermum coincides with Pithecellobium leucospermum sensu McVaugh (1987: 236). As would be expected from its wide dispersal, there is considerable variation at the populational level, especially in indumentum and width of leaflets. Pithecolobium leucospermum sens. str., Ch. langlassei, and Ch. guatemalense answer to the pubescent phase that prevails over the variety’s whole range, and Ch. undulatum to the glabrous one, which occurs randomly through most of the Mexican range of the variety, from Sonora to Oaxaca. Among these segregates Ch. langlassei has relatively narrow leaflets, suggestive of var. mangense, but they are less numerous, as are the pinnae. A long narrow pod, undulately constricted between seeds at the flattened isthmi, combined with the low leaf-formula given above, effectively characterizes the taxon. In Pacific Oaxaca some populations with relatively many and small leaflets might be thought of as intergradient with var. mangense, but have, so far as known to us, the pod of var. leucospermum. Plants of Yucután Peninsula with relatively few and ample leaflets are either intermediate to or perhaps as well referred to var. lentiscifolia.

There is no strong evidence one way or the other bearing on the status of var. leucospermum on Jamaica, Hispaniola, or St. Croix, but, as it is known today by only one record from each island, a hypothesis of casual introduction from the mainland is plausible. The locality in Jamaica (Maxon & Killip 312, NY) is at the port of Kingston where, if native, it could hardly have escaped notice of James Macfadyen, William Harris, or modern collectors; that on Hispaniola (Ekman 5964, NY) is on the south coast of Haiti near the port of Jacmel. Both of these plants represent the less common glabrous variant mentioned above. The record from St. Croix (Liogier 34208, (NY, in bud) requires fruit for confirmation of variety.

The seeds of var. leucospermum are pallid but not really white. Ordinarily the testa is pale fawn-color with a fuscous patch on each face within the pleurogram, but it is sometimes putty-colored overall.