1. Monotropa hypopitys L. (pinesap, false beechdrops)

Hypopitys americana (DC.) Small

Pl. 374 l, m; Map 1642

Stems 8–25 cm long, often clustered, sparsely to densely and minutely hairy, variously yellow or yellowish brown to red, turning dark brown upon drying. Leaves 4–10 mm long, 2–5 mm wide, sparsely to densely and minutely hairy, the margins thin and somewhat irregular. Inflorescences racemes of 3–10 flowers, the flower stalks 4–8 mm long at flowering, elongating to 15 mm at fruiting. Sepals 4 or 5, rarely absent, 7–12 mm long, 1–3 mm wide, lanceolate, erect, minutely hairy on both surfaces and margins. Petals 8–17 mm long, 3–5 mm wide, elliptic to spatulate, minutely hairy on both surfaces and margins. Stamens with the anthers horseshoe-shaped, dehiscing by a single slit across the tip. Ovary 4- or 5-lobed, minutely hairy. Stigma more or less disk-shaped, with a small, circular depression ringed with a fringe of hairs. Fruits with the body 5–6 mm long, 4–5 mm wide, capped by the persistent style, the capsule wall segments relatively thin, usually shed as the fruit dehisces. 2n=16, 32, 48. June–October.

Scattered nearly throughout the state, but absent or nearly so from the Unglaciated Plains Division (U.S., including Alaska; Canada, Mexico, Central America, Europe, Asia). Bottomland forests, mesic to less commonly dry upland forests, ledges of bluffs, and occasionally banks of streams and rivers.

The species epithet is sometimes spelled hypopithys in the botanical literature, based on this unintentional misspelling in Linnaeus’s original description. Monotropa hypopitys is quite variable in such characters as size, color, degree of pubescence, leaf and bract margins, and proportions of ovary and style (Wood, 1961; Wallace, 1974, 1995). Seasonal variation also occurs in the appearance of this species in that plants blooming in the summer tend to be yellowish, whereas those blooming in the autumn are more pinkish or reddish. Rarely, individuals exhibit odd color patterns, such as candy-cane-like striping of red and white or red stems with yellow flowers. More than 80 segregates have been named, but none of these have been considered to warrant taxonomic recognition in the most recent monographs (Wallace, 1974, 1995). However, in a molecular study of Monotropaceae and their fungal associates, Bidartondo and Bruns (2001) found that North American populations both associated with different fungal groups than did Eurasian plants and were widely separated from them in a phylogenetic analysis of plastid gene sequence data. Clearly, further research is required to unravel the complicated patterns of variation in this complex. Future studies may show that two or more cryptic species have been masquerading under the name M. hypopitys.

Seed set in these plants is normally quite high. Bumblebees visit the flowers, but the plants may be mostly self-pollinated, as the anthers shed pollen directly onto the underside of the stigma.