Tribe Malaxideae - The Pollination Biology of North American Orchids: North of Florida and Mexico - page 97

Table 5.2 Data on Liparis (Magrath 2002a)
Character Liparis lilifolia Liparis loeselii

Plant height (cm) 9-25 6-26

2ACEMELENGTHCM 4-15

Flower number 5-31 2-15(19)

Dorsal sepal (mm) 8-11.5 × 1.2-2 4.5-6 × 1-2

Lateral sepals (mm) 8-11.5 × 1.2-2 4.5-5.5 × 1-2.2

Lateral petals (mm) 8.5-12 × 0.2-0.3 4.5-5.5 × 0.5-1

Lip (mm) 8-12 × 6-10 4-5.5 × 2.2-3.5

Column (mm) 3-4 × 1-1.5 2-3 × 0.5-1

Chromosomes (2 n ) 32, 36

Liparis liliifolia (L.) Richard ex Lindley
(Lily-Leaved Twayblade or Large Twayblade)

Habitat and Distribution

L. liliifolia grows in mesic to moist open woods, often along streams and gullies.
Frequently common in early to mid-successional stages or after logging and other
disturbances, it is reportedly rare in the shade of mature forests (Curtis and Greene
1953 ; Sheviak 1974 ; Niemann 1986 ). It is distributed from southeastern Minnesota,
southern Ontario, New Hampshire, and Massachusetts to northern Arkansas and the
Carolinas with a disjunct population in southeastern Oklahoma (Magrath 2002 ).

Floral Morphology

Up to 31 small, resupinate flowers are borne in a loose raceme (Table 5.2 ) (Luer
1975 ). The sepals are light green; the dorsal is erect while the laterals are generally
positioned beneath the lip (Fig. 5.3a ) (Luer 1975 ; Magrath 2002 ). The petals are
purple and pendant. Both petals and sepals have strongly revolute or involute mar-
gins (Fig. 5.3b ). The lip is relatively wide (Table 5.2 ), recurved, and oblate with
minutely erose margins. It is mauve and more or less translucent with darker red-
dish-purple veining (Luer 1975 ). The column is curved, slightly winged apically,
and bears a pair of blunt tubercles on its inner surface near the base (Fig. 5.3a ). Two
pairs of waxy, yellow pollinia are contained within a two-celled, terminal anther
(Magrath 2002 ). There are no caudicles (Pridgeon et al. 2005 ), and true viscidia are
probably also absent. Nectar spurs are lacking, and although Whigham and O'Neill
( 1991 ) observed no nectar, they reported ants foraging on the lip, perhaps indicating
that some nectar may be present here as in Listera cordata (Ackerman and Mesler
1979 ). Although purple flowers sometimes indicate a form of mimicry evolved to
attract insects that feed on or deposit eggs in carrion, the flowers of L. liliifolia are
reportedly odorless (Whigham and O'Neill 1991 ).