Rhizome elongated, horizontal or vertical, usually quite densely covered with roots. Straight or sometimes leaning shoot. Staggered or staggered foliage. Leaves are smooth or slightly rough, flat. Ordinary multiflorous inflorescence, not very dense. Ovary twisted at the root, sitting. The flowers are quite large, white or red, more or less tubular. Two-piece lip, both parts are movably connected. The root part is gutter-like folded, inversely triangular, with a shallow spur at the base. The apical part is triangular to heart-shaped, covered with fine, thick hairs. Straight pillar, slender. The stamen placed at the top of the column, mobile, ovoid. Loose pollen grains, loose, whitish. Cup-shaped birthmark, all his dolls are fertile, middle patch similar to side patches – it does not make any hobbies.
This genus includes approx 12 species, which grow mainly in Asia, Europe and North Africa. They are present in Poland 3 species.
Roundworms are plants of fertile deciduous forests, mainly beech, They can also be found in the clearings and outskirts of forests, less often in the meadows. They prefer calcareous soils, neutral or even slightly alkaline.
Among species of this genus, there is a tendency to lose chlorophyll in leaves and to reduce the number and size of leaf blades. Completely greenless plants have been found many times, with the young, scaly leaves. It is quite common, especially in the red grenadier (Cephalanthera rubra). North American C.. austinae Benth. et Hook. it is even a saprophytic plant, greenless. Sometimes it is treated as a separate genus - Eburyopliyton Heller.
Related to the roundworm is the Mediterranean genus Limodorum (Tourn.) Linn. It covers 2 saprofityczne, leafless species with flowers similar to the flowers of our roundworm. Limodorum aborthwn Sw., found in our southern and western neighbors, it has large flowers, from the lobes of the perianth approx 20-25 mm, and at the base of the lip of a similar size a spur, filled with nectar. The second species, L. tributtianum Batt., only grows in individual positions in Spain, Morocco, Algeria and Tunisia. Its flowers are slightly smaller, and only has a spur 2 mm in length.
The flowers of the roundworms are devoid of nectar. As numerous studies show, They "resemble" the flowers of other insect-pollinating plants, which offer food for insects, e.g.. bell flowers (Campanula). Swordleaf juror (C. longifolia) it is pollinated by species of the genus Halictus (Hymenoptera). The insect on the flower stays for a very short time – 5—15 s, and, as a rule, one visits, rarely two flowers on one plant. These insects, which stay in flowers longer (20-30 s), they leave the grenadiers heavy and seem stunned. They need approx 2-3 min. Halictus sp. collects orange-yellow hairs from the flowers of the roundworm, which mimic the pollen grains of Cistus sahiifolius. They are the so-called. papillae. The pollen grains of Cistus sahńifolius and the roundworm papillas are in terms of color, shape and size (ok. 50 urn) almost identical. However, the flowers of both species differ significantly from each other: Cistus salyiifolius has large radial flowers, resembling poppies, and the roundworm rather small and tubular. In ultraviolet rays, they emit wavelengths of different lengths. Therefore it appears, that the only factor that attracts insects to the flowers of roundworms are these papillas. The phenology of both species is slightly different - Cistus is blooming by Fr. 2 weeks earlier and a month later it blooms from the roundworm. And because the roundworm is also pollinated then, when not growing with Cistus (both have slightly different ranges) in this case we are talking about an optional mimicry. The pollination process in the red roundworm looks slightly different (C. rubra). It is pollinated by the same insects as bluebells, mostly peach-leaved bellflower (Campanula persicifolia), i.e.. by Chelostoma campanularum and Cli. fidiginosum (Megachilidae). Colorimetric analysis of the flowers of both of these species showed, that their spectra are almost identical. However, differences can be seen in the composition of fragrances secreted by their flowers and vegetative parts. However, it is not the smell that makes the roundworm flowers attractive to insects, but just the color. Both the bell, and the roundworm have similar ranges, but they differ phenologically. In the optimum flowering of the roundworm, only single bellflower flowers are fully developed. Orchids take advantage of this, luring insects. This is called. color mimicry.