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little club-spur bog-orchid, small green wood orchid

large round-leaf orchid, large round-leaf rein orchid, lesser roundleaf orchid, round-leaf bog-orchid, round-leaf orchid

Habit Plants 8–47 cm. Plants 17–62 cm.
Leaves

1(–2), on basal half of stem, ascending to spreading, usually abruptly reduced to bracts distally;

blade oblanceolate to oblong, linear-oblong, or elliptic, 3–19 × 0.8–3.5 cm.

2, in subequal basal pair lying on ground;

bracts (very rarely, 0–)1–6, scattered along stem;

blade broadly elliptic to orbiculate or oblate, 5–21 × 3–22 cm.

Spikes

moderately dense.

lax to dense.

Flowers

resupinate, often incompletely so and held at angle, not showy, rather inconspicuous pale green to dull yellowish green;

lateral sepals porrect;

petals ovate to obovate;

lip oblong, obscurely 3-lobed, without basal thickening, 3–7 × 3–4 mm, margins sometimes dentate-lacerate, apex truncate;

spur clavate, 7–13 mm;

rostellum lobes directed downward, very short, truncate;

pollinaria straight or slightly curved laterally;

pollinia fragmenting, pollen masses trailing down onto stigma;

viscidia linear to linear lanceolate;

ovary rather stout, 6–11 mm.

resupinate, rather showy;

calyx mostly greenish white;

corolla mostly white;

lateral sepals reflexed to somewhat spreading;

petals lanceolate-falcate, margins entire;

lip descending to somewhat reflexed, linear-oblong to linear-lanceolate, without basal thickening, 7–17 × 1–2.5 mm, margins entire;

spur slenderly clavate, 14–27 mm;

rostellum lobes directed strongly forward, wide-spreading, angular;

pollinaria nearly straight, 3–4.5(–4.8, very rarely) mm;

pollinia remaining enclosed in anther sacs;

viscidia orbiculate;

ovary slender to rather stout, mostly 10–26 mm.

2n

= 42.

= 42.

Platanthera clavellata

Platanthera orbiculata

Phenology Flowering summer (Jun–Aug). Flowering Jun–Aug(–Sep).
Habitat Sphagnum bogs, sphagnous seeps and meadows, wet sandy and peaty meadows, marshes, low woods, wet prairies, and roadsides Mesic to wet coniferous and deciduous forest, fen forest
Elevation 0–2000 m (0–6600 ft) 0–1500 m (0–4900 ft)
Distribution
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KY; LA; MA; MD; ME; MI; MN; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; NB; NF; NS; ON; PE; QC
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; ID; IL; IN; MA; MD; ME; MI; MN; MT; NC; NH; NJ; NY; OH; OR; PA; SD; TN; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NF; NS; NT; ON; PE; QC; SK
[WildflowerSearch map]
[BONAP county map]
Discussion

In common with Platanthera nivea and P. integra, the column of P. clavellata bears a series of lateral projections that are directed forward; the upper pair is elaborately adorned and may be glandular. It appears that this species is inappropriately placed in Platanthera. See note under 30. P. nivea

The broader leaves cited as distinguishing Platanthera clavellata var. ophioglossoides are more prevalent in the North, but occur throughout the range of the species. In some areas populations commonly display a complete range of leaf shape; this feature alone is of no taxonomic significance.

The unusual and infrequent hybrid Platanthera blephariglottis × P. clavellata is P. ×vossii Case.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

The key will permit determination of most specimens of Platanthera orbiculata and P. macrophylla. More precise discrimination of ambiguous specimens is possible by use of the formula from A. H. Reddoch and J. M. Reddoch (1993): spur length + (2 × pollinarium length), which for P. orbiculata is less than 38 and for P. macrophylla is equal to or greater than 38.

Considerable variation in size and shape of leaves occurs, and although to some extent regional in nature, intergradation is complete; recognition of infraspecific taxa is unwarranted. A few collections from isolated areas on the Pacific Coast of Canada are noteworthy, however. Those are small, few-flowered plants with rather narrow leaves borne alternately or suboppositely toward the base of the stem, as in some Asiatic species. They are in some respects very similar to Platanthera freynii Kränzlin, an Asiatic species distinguished primarily by its abruptly narrowed petals, in contrast to the generally broader, but variable, petals in North American plants. These western plants warrant further study to establish their identity and to elucidate relationships between North American and Asiatic species.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 26, p. 570. FNA vol. 26, p. 555.
Parent taxa Orchidaceae > subfam. Orchidoideae > tribe Orchideae > subtribe Orchidinae > Platanthera Orchidaceae > subfam. Orchidoideae > tribe Orchideae > subtribe Orchidinae > Platanthera
Sibling taxa
P. aquilonis, P. blephariglottis, P. brevifolia, P. chapmanii, P. chorisiana, P. ciliaris, P. convallariifolia, P. cristata, P. dilatata, P. flava, P. grandiflora, P. hookeri, P. huronensis, P. hyperborea, P. integra, P. integrilabia, P. lacera, P. leucophaea, P. limosa, P. macrophylla, P. nivea, P. obtusata, P. orbiculata, P. peramoena, P. praeclara, P. psycodes, P. purpurascens, P. sparsiflora, P. stricta, P. tipuloides, P. zothecina
P. aquilonis, P. blephariglottis, P. brevifolia, P. chapmanii, P. chorisiana, P. ciliaris, P. clavellata, P. convallariifolia, P. cristata, P. dilatata, P. flava, P. grandiflora, P. hookeri, P. huronensis, P. hyperborea, P. integra, P. integrilabia, P. lacera, P. leucophaea, P. limosa, P. macrophylla, P. nivea, P. obtusata, P. peramoena, P. praeclara, P. psycodes, P. purpurascens, P. sparsiflora, P. stricta, P. tipuloides, P. zothecina
Synonyms Orchis clavellata, Habenaria clavellata, Habenaria clavellata var. ophioglossoides Orchis orbiculata, Habenaria orbiculata, Habenaria orbiculata var. lehorsii, Habenaria orbiculata var. menziesii, P. orbiculata var. lehorsii
Name authority (Michaux) Luer: Native Orchids Florida, 148. (1972) (Pursh) Lindley: Gen. Sp. Orchid. Pl., 286. (1835)
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