Hypericum mexicanum (Nomenclature)
Shrub or shrublet 0.15-l.5(-2) m tall, erect or decumbent and sometimes rooting at the base, with branches strict, pseudo-dichotomous and sometimes lateral especially from short upper internodes. Stems yellow-brown to orange-brown, 4-lined when young, eventually terete, cortex flaking irregularly; internodes 2-8 mm long. Leaves sessile, outcurving-ascending to imbricate-erect, tetrastichous, deciduous above base usually without withering; lamina 7-17 x 3-10 mm, elliptic or oblanceolate to obovate, plane to subconduplicate, not or scarcely cucullate, not carinate, concolorous, not glaucous, coriaceous; apex obtuse or rounded, base cuneate to angustate, ± sheathing, pairs united to form narrow interfoliar ridge; basal veins 5-7, flabellate, branching and anastomosing distally, reticulation clearly to obscurely visible beneath; laminar glands dense to sparse, usually visible and sometimes slightly prominent beneath; marginal glands secreting viscous clear or white resin. Inflorescence l-5(-13)-flowered, cymose, corymbose, often with 1-3 pairs of pseudo- dichotomous branches from 1-3 nodes close below; peduncle and pedicels 1-6 mm long; upper leaves transitional. Flowers 15-25 mm in diam., stellate. Sepals 5-9 x 2-4 mm, elliptic to oblanceolate-spathulate or obovate, acute to apiculate or obtuse; veins 5-9, sometimes dichotomising distally, with midrib scarcely prominent beneath; glands punctiform distally. Petals golden yellow, (always?) tinged red beneath, 9-12 x 4-9 mm, 1.3-2 x sepals, obovate-oblanceolate to obovate-oblong; apiculus obtuse to obsolete; glands punctiform distally. Stamens c. 50, longest 5-7 mm long, c. 0-5 x petals. Ovary 2.5-3 x 1.8-2 mm, broadly ellipsoid to ovoid; styles 3, 2.5-4 mm long, 1-1.2 x ovary, suberect; stigmas broadly capitate. Capsule 5-7 x 4-6 mm, broadly ellipsoid to subglobose, equalling or exceeding sepals. Seeds c. 0.7 mm long, ecarinate; testa finely scalariform.
In open paramo on fine talus or grassy slopes or in scrub; (1700)2400-4200 m.
Western Venezuela (Mérida, Táchira) and north-eastern to central Colombia (Norte de Santandér to Valle de Cauca). Map 12.
H. mexicanum is a misnomer, as the type comes from Cundinamarca and the species as a whole is confined to Colombia and adjacent Venezuela. In attributing Mutis collections to Mexico, Linnaeus made the same mistake here as he did in the case of Vismia baccifera.
H. mexicanum differs from H. gleasonii in having larger, more spreading leaves and smaller flowers, which are frequently in condensed cymes. The two species remain distinct where their distributions overlap in the Páramo del Almorzadero.
Gleason (1929) confused the eastern form ofH. mexicanum with H. platyphyllum, which has penninerved (not flabellate-nerved) leaves and smaller stigmas and is treated here as a subspecies of H. phellos.