Hypericum lorentzianum
Subshrub 0.15-0.4(-l) m tall, erect, 1-stemmed, with branches ascending to spreading, lateral, numerous, sometimes becoming naked below. Stems reddish-brown, incompletely 4-lined, ancipitous when young, eventually terete, cortex exfoliating in strips; internodes 5-7.5 mm long, shorter than to exceeding leaves. Leaves sessile, spreading; lamina 7-20 x 1-3 mm, narrowly elliptic to oblong-linear or oblanceolate, plane to recurved, paler beneath, not glaucous, chartaceous; apex obtuse to rounded, base cuneate to parallel-sided, not decurrent, free; basal veins 1-3, midrib with 1-4 main pairs of branches, tertiary reticulum obscure or absent (?) laminar, glands dense, not prominent. Inflorescence c. 7-c. 80-flowered, dichasial/monochasial without accessory branches, with lateral branches from up to 7 nodes below, the whole obovoid to corymbiform, partial inflorescences densely subcorymbiform to corymbiform (i.e. flat-topped); primary pedicels 1.5-2.5 mm long; bracts and bracteoles oblong-linear to linear. Flowers 7-10 mm in diam., stellate; buds ovoid-ellipsoid, obtuse. Sepals 2.5-4 x 0.5-1.1 mm, subequal, imbricate, lanceolate or narrowly oblong to narrowly elliptic, acute; veins 5, inner 3 becoming prominent; glands all linear or sometimes distally punctiform. Petals yellow, 4-5 x 2-3 mm, c. 1.6-2 x sepals, oblong-elliptic, apiculus very short or obsolete; glands interrupted-linear to punctiform. Stamens 40-50, obscurely 5-fascicled or irregular, longest 2-3 mm long, c. 0.5-0.6 x petals. Ovary 1-1.5 x 0.8-1 mm, broadly ovoid to subglobose; styles (5)4(3), 1.6-2 mm long, 1.3-2 x ovary, spreading; stigmas narrowly capitate to scarcely enlarged. Capsule 2.5-4 x 2-3 mm, broadly ovoid to globose, shorter than or equalling sepals. Seeds c. 0.5 mm long; testa ribbed-scalariform.
Shaded grasslands, woodland margins; 20-1400 m.
Brazil (Paraná, Santa Catarina, Rio Grande do Sul), Paraguay, Argentina (Salta, Misiones, Corrientes), Uruguay.
H. lorentzianum is a morphological link between H. campestre subsp. campestre and H. myrianthum, having smaller leaves, smaller flowers, and a more condensed (often flat- topped) inflorescence than the former and larger flowers and a less condensed inflorescence than the latter. Extreme morphological reduction occurs in Uruguay, but such plants are not likely to be confused with H. myrianthum because the flowers are larger and the habit dwarfer than in that species.