Pterospora

Herbs, achlorophyllous, heterotrophic. Stems absent. Leaves absent. Inflorescences racemes, erect at emergence from soil, axis fleshy and fibrous, persistent after seed dispersal, pink to reddish or brownish, 0.5-1.5 cm diam. proximal to proximalmost flower. Pedicels decurved, somewhat longer in fruit; bracteoles absent. Flowers radially symmetric, nodding; sepals 5, distinct, lanceolate-ovate; petals 5, connate, cream to yellowish or white, without basal tubercles, (surfaces glabrous), corolla urceolate; intrastaminal nectary disc present; stamens 10, included; filaments broader proximally than distally, glabrous; anthers depressed-ovoid to ovoid, with awns, without tubules, dehiscent by 2 oval slits; pistil 5-carpellate; ovary 5-locular; placentation axile; style straight, slender; stigma capitate, without subtending ring of hairs. Fruits capsular, pendulous, dehiscence acropetally loculicidal, no cobwebby tissue exposed by splitting valves at dehiscence. Seeds 100+, ovoid, with broad, rounded, membranous wing attached at 1 end. x = 8.

PLANT: Flowering stems erect, fleshy, reddish-brown, densely glandular-hairy, 1-several from a dense spherical root mass, to 1 m tall, the inflorescence terminal; bracts triangular, overlapping, clustered near base of stem, becoming reduced linear-lanceolate and scattered above, merging with the inflorescence bracts. FLOWERS: nodding, whitish, yellow or pink, numerous in an elongate, open raceme-like inflorescence, at times clustered in groups of 2-5; sepals 5, separate, linear-lanceolate, glandular, to 5 mm long; corolla fused, urn-shaped, persistent, the lobes 5, reflexed; stamens 10, the filaments smooth; anthers ovoid with two recurved awns the length of the sacs; pollen grains four-grooved, many aborted; style short, columnar; stigma capitate, obscurely 5-lobed. FRUITS: 5-locular, nodding, depressed-globose capsules, 8-12 mm wide. SEEDS: ovoid, tapered to one end, with 5 ribs and a conspicuous rounded wing larger than the seed body. NOTES: A monotypic N. Amer. genus, widely distributed but mainly with a bicentric range, in coniferous forests of w and ne N. Amer. and Mex. (Greek: pteron = wing + sporos = seed, for the conspicuously enlarged wing attached at one end of the seed). REFERENCES: Haber, Erich. 1992. Monotropaceae. Ariz.-Nev. Acad. Sci. 26(1)2.

Cor gamopetalous, urceolate, 5-lobed, persistent; stamens 10; filaments flattened, elongate; anthers thick-triangular, somewhat inflexed but not strongly inverted, each pollen-sac opening by a large lateral slit and with a retrorse, filiform appendage at the morphological base; ovary 5-locular; style columnar, short; stigma fleshy, capitate, shallowly 5-lobed; capsule depressed-globose, deeply umbilicate, loculicidal, opening from the morphological base toward the distal end; seeds with a broad terminal wing; pink to reddish or purplish (or eventually brownish) plants with small scale-lvs and long racemes of nodding fls and frs. Monospecific.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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