The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

grass pink orchid, tuberous grass-pink

Habit Plants 4–110(–135) cm.
Leaves

not appressed to inflorescences at flowering;

blade linear, lanceolate, or seldom elliptic-lanceolate, 2–50 cm × 2–35(–50) mm, margins slightly to strongly curled transversely.

Inflorescences

green or slightly purple at base, becoming entirely green after flowering, 4–135 cm;

floral bracts ovate to ovate-lanceolate, subulate, 3–30 mm.

Flowers

1–25, opening sequentially, magenta, pink, to white, faintly fragrant;

dorsal sepal oblanceolate, 15–31 × 5–18 mm, apex acuminate;

lateral sepals occasionally reflexed distally, ovate to lanceolate, slightly falcate, 13–26 × 5–16 mm, apex apiculate to acuminate;

petals obpandurate to seldom elliptic, slightly falcate, 15–28 × 4–14 mm, apex obtuse;

lip 11–23 mm, middle lobe with dilated end typically anvil-shaped, seldom triangular, 5.5–21 mm wide;

column 12–25 × 1–2 mm, distal end 4.5–10 mm wide;

rostellum present or absent;

stigma at angle to column surface.

Capsules

ovoid to ellipsoid, 13–30 × 5–10 mm.

Corms

globose to elongate, not forked, 8–31 mm.

2n

= 26, 40, 42.

Calopogon tuberosus

Distribution
from USDA
e North America; West Indies (Bahamas, Cuba)
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

Calopogon tuberosus is the most variable and widespread species in the the genus. It occurs from Manitoba and Newfoundland south to Texas, Florida, the Bahamas, and Cuba.

Calopogon tuberosus can be distinguished from other species in the genus where sympatric by its relatively robust size and elongated lip with wide, anvil-shaped dilated distal end. Plants with a triangular-shaped middle lip lobe are uncommon in the south and occur toward the northern part of the range, and those with long but narrowed lips occur in C. tuberosus var. simpsonii, the latter plants generally being much larger and occurring in a different habitat than all other species of Calopogon.

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

Key
1. Leaf blade slightly curled transversely; dilated distal portion of middle lip lobe broadly expanded and not whitened except in entirely white flowers; acidic wetlands.
var. tuberosus
1. Leaf blade strongly curled transversely; dilated distal portion of middle lip lobe narrowly to widely expanded, whitened; wet, alkaline savannas.
var. simpsonii
Source FNA vol. 26, p. 600.
Parent taxa Orchidaceae > subfam. Epidendroideae > tribe Arethuseae > subtribe Bletiinae > Calopogon
Sibling taxa
C. barbatus, C. multiflorus, C. oklahomensis, C. pallidus
Subordinate taxa
C. tuberosus var. simpsonii, C. tuberosus var. tuberosus
Synonyms Limodorum tuberosum
Name authority (Linnaeus) Britton: Prelim. Cat., 52. (1888)
Web links