Zygia picramnioides

  • Title

    Zygia picramnioides

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Zygia picramnioides (Standl. ex Killip) Killip

  • Description

    18. Zygia picramnioides  (Britton & Killip) Killip, Ann. New York Acad. Sci. 35: 19, ad calcem. 1936. Pithecellobium picramnioides Standley ex Britton & Killip, Ann. New York Acad. Sci. 35: 192. 1936. — "El Humbo region, Boyacá, Colombia . . . 750 m, March 1933, A. E. Lawrance 718." — Holotypus, F n.v.; isotypi, A!, K!, US 2324102!. —Zygia picramnioides (Standley) L. Rico, Kew Bull. 46: 504 ("comb. nov.," without explanation). 1991. — If simultaneous publication of Pithecellobium and Zygia picramnioides, the second in a correcting footnote, invalidates the combination Z. picramnioides, it also invalidates P. picramnioides, and Z. picramnioides becomes a new species, not a new combination.

    Pithecellobium picramnioides sensu Barbosa, 1989: 4; 1991: 321.

    Macrophyllous cauliflorous trees 6-9 m with trunk 1.5-2 dm diam, the terete barren foliate branches and lf-axes thinly puberulent with sordid hairs 0.1-0.3 mm, the foliage bicolored, the thinly chartaceous lfts when dry dull brown and glabrous above, beneath paler and pilosulous along principal nerves, the long lax spikes of white-stamened fls fasciculate on knots of older wood, their axes densely brown-yellow- pilosulous throughout. Stipules firm, lanceolate 9-12 x 2-3 mm, persistent; axillary resting-buds of lanceolate, distally falcate, conduplicately imbricate, internally striate scales ±12-18 mm. Lf-formula 1/3½-4½, the lfts 14 or 18 per If; lf-stks including pulvinus (2-) 2.5-4.5 cm, at middle 2-4 mm diam; a subsessile button-shaped nectary at apex of lf-stk attaining 4.5 mm diam, a smaller one between furthest lft-pairs; pinna-rachises 13-26 cm, the interfoliolar segments 4—6 cm; lft-pulvinules stout, in dorsal view 4—7 x 2.4—2.7 mm; lfts ovate or elliptic-(ob)ovate from inequilaterally cuneate base, shortly acuminate and sharply acute at very apex, the larger ones 11-14 x 4.5-6 cm, 2.2-2.6 times as long as wide; venation almost immersed on upper face of lfts, sharply elevated beneath, the scarcely displaced midrib either straight or gently incurved, giving rise on each side to 8-9 pairs of incurved-ascending secondary nerves weakly brochidodrome close within the plane margin, the first pair produced scarcely or not to midblade, the tertiary connecting venules slender sinuous, not generating a defined reticulum of veinlets. Axis offl-spikes, including peduncle, (8-) 15-32 cm, the fls well separated  along it; bracts deflexed, ovate, scarcely 1 mm, caducous; perianth pale brown, minutely silky overall; calyx sessile or raised on a thickened pedicel <0.3 mm, campanulate 1-1.3 x 1-1.4 mm, the depressed- deltate teeth at most 0.2 mm; corolla slenderly trumpet-shaped ±8.5 mm, the erect, ovate lobes ±2 mm; androecium ±60-merous, the tassel (white acc. collector) not seen fully expanded, the length of mature tube therefore unknown; lobed intrastaminal disc ±0.3 mm; ovary linear-ellipsoid glabrous. Pods unknown.

    Overhanging a stream in dense forest, near 750 m, at the type locality in mun. Muzo, near 5°35'N, 74°7/W in the W arm of state of Boyacá, Colombia, and formerly near Barranca Bermeja in adj. Santander; reported by Barbosa (1989: 4) from dept. Valle. — Not mapped. — Fl. III-IV.

    Zygia picramnioides closely resembles some forms of Z. coccinea var. oriunda, except that the latter is exclusively Amazonian in dispersal and has shorter leaf-stalks, <1.5 cm (as opposed to 2.5-4.5 cm) in larger leaves. Fruits, of course, may yet provide supportive characters.