Which plants display the showiest, most flamboyant flowers? Some will insist that they are the various orchid species.


The orchid family truly is a giant group, easily the largest plant family in the world, in terms of number of different species. Orchids as a family cover the earth – almost. They are known from all but the coldest parts of the planet.


Many are epiphytic, or growing on the branches of trees, but quite a large number, too, are terrestrial, at home on the ground. (Some are even weeds.) Orchids typically have sheathing leaves on the stems, which are alternating, one at each node. There is a tremendous variety of flower shapes, but they all follow a basic theme.


Two very interesting things for some people to realize are that orchid species aren’t all tropical, and that there are plenty of these species that don’t have big, showy corsage-quality blossoms.


In fact, some of these species have flowers that are very tiny and inconspicuous. Something else: all orchid species produce a dry capsule as a fruit, and it will be packed with lots of lots of extremely tiny seeds: probably the smallest seeds of ant plant group.


Native, or wild, orchids are always a crowd-pleaser. In the Southeastern United States, there are plenty of native orchid species, and some of these have relatively large, spectacular flowers.


Among these striking orchids are the lady-slippers, grass-pinks, whorled pogonia, rosebud orchid, bog-rose and showy orchids. Other orchids in our area have flowers that are a bit more modest. This week’s Mystery Plant is a species in the latter group.


It is a bit unusual in that it is aquatic, mostly seen in very wet places, often in ditches or ponds, sometimes as a component of soggy, floating mats. For some reason it seems to like golf-course ponds.


It occurs from southern Virginia all the way to eastern Texas, and then south into South America. In our area, it is a fairly common wetland plant, but it’s often overlooked. The stems bear many leaves, which tightly them.


The sword-shaped leaves themselves are bright green, or sometimes yellowish. In fact, the flowers tend to be greenish, sharing the color of the foliage, and so the flowers tend to be somewhat inconspicuous.


These flowers are typical of orchids, though, in bearing three sepals and three petals. Each of the two upper petals is cleft into a pair of narrow segments. The third, lowest petal is also deeply divided, but into three very narrow, wiggly, thread-like portions.


The whole effect of all this is that the flowers, which are crowded into a spike, appear something like little green spiders crawling around.


The plants often develop slender, pale runners which can produce new flowering stems. This water-lover is blooming now, and will continue until frost.


It can be expected in just about all of the coastal plain counties of Georgia and South Carolina, and the more southern of those in North Carolina.


John Nelson is the curator of the A. C. Moore Herbarium at the University of South Carolina, in the Department of Biological Sciences, Columbia. As a public service, the Herbarium offers free plant identifications. For more information, visit www.herbarium.org or call 803-777-8196, or email nelson@sc.edu.


Answer: “Water-spider orchid,” Habenaria repens