Cojoba graciliflora
Rupert C. Barneby
9. Cojoba graciliflora (Blake) Britton & Rose, N. Amer. Fl. 23: 31. 1928. Pithecellobium graciliflorum Blake, Contr. Gray Herb. 52: 69. 1917. — "British Honduras: open ground, Toledo, 2 June 1907, M. E. Peck 921." — Holotypus, GH!; isotypi F!,K!, NY!.
C. donnell-smithii Britton & Rose, N. Amer. Fl. 23: 30. 1928. — "Yzabel [=Yzabal], Guatemala, April 1889, John Donnell Smith 1733." — Holotypus, US 942470!. — Pithecellobium donnell-smithii (Britton & Rose) Standley, Trop. Woods 34: 40. 1933.
C. tenella Britton & Rose, N. Amer. Fl. 23: 31. 1928. — "Along Stann Creek, British Honduras, January 27, 1926, Samuel J. Record." — Holotypus, US 1265374!; isotypus (fragm.), NY!. — Pithecellobium tenellum (Britton & Rose) Standley, Publ. Field Mus. Nat. Hist., Bot. Ser. 10: 216. 1931.
C. recordii Britton & Rose, N. Amer. Fl. 23: 31. 1928. — Near Botanic Station, Lower Belize River, British Honduras, February 19, 1926, Samuel J. Record." — Holotypus, NY!; isotypus, NY (fragm.)!. — Pithecellobium erythrocarpum Standley, Trop. Woods 34: 40. 1933, non P. recordii Standley, 1929.
Pithecolobium gentlei Lundell, Contr. Univ. Michigan Herb. 6: 28. 1941. — "British Honduras: El Cayo District, Water Hole, near Vaca, on hillside, April 5, 1938, Percy H. Gentle 2452." — Holotypus, MICH!.
P. plumosum Lundell, Contr. Univ. Michigan Herb. 6: 30. 1941. — "BRITISH HONDURAS: El Cayo District, Mountain Pine Ridge . . . Feb. 21, 1931, H. H. Bartlett 11627." — Holotypus, MICH!.
P. schippii Lundell, Contr. Univ. Michigan Herb. 6: 31. 1941. — "British Honduras, Toledo District, Temash River, in swamp forest in shade, . . . April 3, 1935, W. A. Schipp 1318." — Holotypus, MICH!; isotypi, F!, MO!, NY!.
Small shrubs flowering at 1 m or less to trees to 15 m tall, peduncles and young stems densely charged with long red, more or less straight hairs to 0.4-0.6 mm and puberulent with incurved-ascending or erect blond or blond-red hairs 0.1—0.2 mm, the annotinous stems less so, the dorsal side of lf-axes moderately to densely pubescent with the blond or blond-red hairs, likewise the fruit, densely so along the sutures and the isthmi, sparingly so on the valves over the seed-cavities, the bicolored, thin-textured to (larger ones) somewhat leathery lfts ample, green-lustrous on the upper surface, paler on the lower, glabrous or puberulent on midrib, the dorsal or both faces occasionally uniformly moderately red-blond-hispidulous, the capitula of white flowers 1—2 in the axils of coeval leaves. Stipules narrowly lanceolate, linear or linear-cylindroid, 1.5-5 mm, nearly always persistent until the lf is fully expanded, commonly for some time after. Lf-formula (i—)ii—v/7— 18; the terete or semi-terete lf-stks 1.9-15.2 cm, the petiole proper 0.9-3.3 cm, the longer interpinnal segments 1-3 cm, the lf-stk charged immediately above the pulvinus or between the first pinna-pair with a crateriform to short-stalked thick-rimmed cupular nectary 0.5-1.25 mm diam, one (or between pinna-pairs 2) similar but smaller nectary between all pinna-pairs, between all leaflet-pairs, and surmounting the pinna-pulvinus, that on the pinna-pulvinus accompanied by two linear paraphyllidia 0.5-0.75 mm long; pinnae at least slightly accrescent distally, the longer ones 5.5-15 cm long, the interfoliolar segments 4—14 mm; the lft-pulvinules ovate or somewhat falcately broadly elliptic 0.5-1.5 mm on the long axis, coarsely wrinkled, glabrate or pubescent on dorsal side only, or on both sides; lfts falcately or asymmetrically lance-elliptic, lance-ovate or ovate-elliptic from an inequilaterally broadly attenuate to somewhat semicordate base, distally accrescent except for the sometimes somewhat slightly smaller terminal pair, the longer ones 1.4-4.1 x 0.4-2 cm, 1.8-3.8 times longer than broad, the apex broadly acute or rounded, the subcentric midrib faintly or pronouncedly distally falcate; venation pinnate-palmate with 2-3 nerves from pulvinule brochidodrome well below midblade, the secondary and tertiary veins faint on the upper surface, prominent beneath and usually lightly brownish-discolored. Peduncles 3-7.6 cm, at any one node subequilong, though those of different nodes on the same shoot often of widely disparate length, charged or not immediately below the capitulum or 3/4 of the distance up the peduncle with an ascending-incurved, usually somewhat thickened, lanceolate to ovoid-lanceolate bract 3-7 mm long, the globose capitulum 44-54-flowered, the receptacle ±2-3 mm diam, the linear or narrowly linear-elliptic red-pubescent bracts (1—)3—7.5 mm long, much longer than buds, persistent past anthesis and abscission of fls; perianth 5-merous, papery, glabrous save for pubescent calyx- and corolla-lobes; calyx cylindrical-campanulate 2.5-5 mm, contracted to and thickened but not stipitate base more or less isodiametric with lower calyx-tube, the equilong to very unequal, usually densely red-pubescent lobes 0.250.75 mm long; corolla narrowly cylindrical-campanulate or cylindrical-urceolate-campanulate (broadest below the throat) 9-16 mm long, the erect to gently arcuate but not reflexed, deltate or lance-deltate lobes subequilong or unequal 0.75-2 mm, densely or rarely rather sparingly red-blond- or blond-pubescent; androecium 21-35-merous, 10-25 mm, the stemonozone 1.5-2.75 mm, the staminal tube 5-15 mm, usually included in corolla, very rarely exceeding it; ovary elliptic subsessile, glabrous overall or the apex minutely red-blond-puberulous, the style centric to slightly ventrally displaced, exceeding stamens; stigma poriform. Pods 1-3 per capitulum, moniliform or submoniliform 12-19 cm long, ±0.7-1.3 cm over seed-cavities, when well fertilized 4—15-seeded, the isthmi nearly absent or to 1.5 mm long, the bright red valves externally evenulose, blond-red-puberulent particularly along sutures and in isthmi, much less so over seed-cavities, usually smooth, becoming coarsely wrinkled with age, internally pale tan-lustrous; dehiscence through both sutures, the valves twisting; seeds ellipsoid or ovoid-ellipsoid 9-11 x 6-7 x 6-7 mm, only rarely somewhat mutually compressed, the shiny black seed-coat usually longitudinally striate when fresh, the striations or a rectangular pattern visible with magnification when dry, the papery but rather tough-resilient coat free from the embryo, at least in part; embryo straight, the eophylls densely long-red-pubescent.
Recorded nearly always in wet forest or along streams from sea level to 1600 m; on the Caribbean slope of the Cordillera in Central America from near Xalapa, Veracruz, S through Chiapas and Quintana Roo in Mexico, and more or less continuously through Guatemala, Belize, and Honduras into Nicaragua; not recorded from El Salvador. — Map 17. — Fl. nearly any time of year, apparently sometimes continuously throughout the year.
Cojoba graciliflora is particularly variable in leaf- formula, bract-length, and flower-length. Pithecolobium tenellum, P. donnell-smithii, and the other species listed in synonymy were all based on extremes in one or another of these characters. However, the variation in any of these is continuous, there is no correlation with geography, and variation in leaf-characters is great even on one individual. For instance, flush leaves when present with late leaves are nearly always of a much higher leaf-formula. In contrast, bract length and flower length are nearly consistent on any one individual.
References: [Article] Barneby, Rupert C. & Grimes, James W. 1997. Silk tree, guanacaste, monkey's earring: A generic system for the synandrous Mimosaceae of the Americas. Part II.