Platanthera brevifolia
Platanthera purpurascens
platanthera de hoja corta, short-leaf bog-orchid, shortflower bog orchid
purple-petal bog orchid
few, ascending-sheathing, little more than bracts, scarcely reduced distally;
bracts often lacking;
blade ovate to elliptic-ovate, 2.5–6 × 0.7–2 cm.
few–several, abruptly diverging or sometimes ascending, scattered along stem;
blade oblong to ovate or lanceolate, 5.5–16(–28) × 1–4.5 cm.
lax to rather dense.
very lax to dense, flowers sometimes irregularly grouped in fascicles.
resupinate, not showy, green to yellowish green;
lateral sepals reflexed or sometimes spreading;
petals ovate- to lance-falcate, margins entire;
lip descending or reflexed, linear to linear-oblong or linear-lanceolate, 6–10(–14) mm, margins entire, often with series of low parallel ridges on adaxial surface;
spur cylindric or tapering toward apex, 9–20 mm, apex usually rather acute;
rostellum lobes somewhat divergent, directed forward, rounded-subangular, rather prominent;
pollinaria straight;
pollinia remaining enclosed in anther sacs;
viscidia orbiculate to broadly elliptic-oblong;
ovary rather slender to stout, mostly 6–12 mm.
resupinate, not showy, green to yellowish green, often suffused with blue or lip sometimes with red;
lateral sepals spreading to reflexed;
petals ovate- to lance-falcate, margins entire;
lip descending to somewhat reflexed or projecting, lanceolate to ovate, sometimes with prominent suborbiculate basal dilation, without basal thickening, 4–8 × 1.5–3 mm;
spur strongly clavate to scrotiform, 2–3 mm, apex obtuse;
rostellum lobes strongly diverging, very small, rounded, obscure;
pollinaria straight;
pollinia remaining enclosed in anther sacs;
viscidia orbiculate to oblong;
ovary rather slender to stout, mostly 5–9 mm.
= 42 [63].
Platanthera brevifolia
Platanthera purpurascens
The greatly reduced herbage of Platanthera brevifolia is distinctive. Robust plants may lack developed leaves altogether, with merely a few reduced bracts at the base of the stem and an inflorescence comprising nearly the entire height of the plant. A strong mycotrophic mode is suggested by the occurrence in some colonies of truly albino plants without pigmentation.
Platanthera brevifolia largely replaces P. sparsiflora in Mexico and is very distinctive at its northern limit in the United States. Although P. sparsiflora is exceedingly variable in floral dimensions, in habit, and in the number, size, and placement of leaves, the pattern seen in P. brevifolia seems to lie outside this range of variation. With a generally longer spur and very different ecologic requirements, it is here treated at the specific level. Nonetheless, P. brevifolia is reported to intergrade with P. sparsiflora in Mexico (R. McVaugh and W. R. Anderson. 1974+, vol. 16, pp. 254–256), yet the latter species probably does not range there beyond a possible occurrence in Baja California (M. A. Soto 1988).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Flowers of Platanthera purpurascens are strongly semen scented, and their musty scent is markedly different than the sweet and spicy scents of other fragrant species.
In some areas this species hybridizes with Platanthera dilatata var. albiflora, producing sweetly fragant plants with lanceolate green lips. At the southern edge of its range, however, it often occurs with similar plants in the absence of another putative parent. The identity of these plants is uncertain. Their rather generalized morphology might mask polyphyletic origins.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
WildflowerSearch
iNaturalist
USDA Plants Database
CA
