28. Hypericum hypericoides (Linnaeus) Crantz, Inst. Rei Herb. 2: 520. 1766.
St. Andrew’s cross St. Andrew’s cross
Ascyrum hypericoides Linnaeus, Sp. Pl. 2: 788. 1753
Subshrubs or shrubs, erect or decumbent to prostrate, unbranched or branched, sometimes diffuse and mat-forming, 0.5–3 or 3–15 dm. Stems: internodes 2-winged. Leaf blades oblanceolate or narrowly oblong or elliptic to linear, 7–25 x 1–8.5 mm, base not articulated, usually cuneate, sometimes rounded, <with glandlike auricles>, margins subrecurved, apex rounded to obtuse, midrib with 1–2 pairs of branches. Inflorescences <narrowly cylindric to pyramidal>, 1–12-flowered from 1–4 nodes, sometimes with branches from to 10 proximal nodes, or branching more elaborate and pseudodichotomous; <pedicels erect in fruit, bracteoles distal>. Flowers 10–20 mm diam.; sepals persistent, enclosing capsule, 4, unequal, outer ovate-suborbiculate to narrowly elliptic, 5–12.5 × 2–13 mm, <apex subapiculate to obtuse>, inner lanceolate, 1–4 × 2 mm, <apex acute>; petals 4, bright to pale yellow, obovate to narrowly oblong-elliptic, 6–12 mm; stamens persistent, 40–50; ovary 2-merous. Capsules narrowly compressed-ovoid to cylindric-ellipsoid, 5–9 × 2–4 mm. Seeds not carinate, 0.6–0.8 mm; testa finely linear-reticulate to linear-foveolate.
Subspecies 3 (2 in the flora): c, e United States, Mexico, West Indies (Bahamas, Greater Antilles), Bermuda, Central America (Guatemala, Honduras).
Hypericum hypericoides can be distinguished from H. crux-andreae by the two-merous ovary, narrower leaves, smaller flowers, and more richly-branched stems. It is variable in leaf and sepal shape and size; three subspecies can be recognized.
The erect bushy form (subsp. hypericoides) is most widespread and has given rise to a northern diffuse form (subsp. multicaule) in the United States and a prostrate form (subsp. prostratum N. Robson) in Hispaniola.