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Sunday, November 1, 2015

Gone to Seed

Scarlet Leatherflower, Clematis texensis

Often used as an informal figure of speech meaning to deteriorate or go downhill, ‘gone to seed’ can have a negative connotation.  But each seed contains a new beginning: a tiny plant just waiting for the right conditions such as water, warmth, and a good location, to germinate and grow.  Seeds and seed heads form fascinating shapes, varying sizes, and intricate patterns, often adorning the fall and winter landscape.

Illinois Bundleflower, Desmanthus illinoensis

Inland Sea Oats, Chasmanthium latifolium

Plants have many ways of dispersing their seeds, and most have evolved over millions of years. While the methods are tried and true, certain seeds have developed in very particular ways to take advantage of such methods, and some plants only release their seeds in response to specific triggers. 

Wafer Ash, Ptelea trifoliata

Texas Milkweed, Asclepias texana

Wind helps seeds float or flutter away, often aided by seed structures such as thin wing extensions or long, feathery tails like those on the endemic Scarlet Clematis (Clematis texensis).  Texas Bluebonnets (Lupinus sp.) employ the expulsion or explosion method, where the small, pebble-like seeds are forcibly expelled when the dried pods twist open in the warm sun.  Gravity plays a part in many plants seed dispersals, where weighty seeds fall off the plant and roll to a new location.  The best example of this are the round, heavy fruits that simply fall off a plant when ripe, such as those on Mexican Plum (Prunus mexicana) or Texas Persimmon (Diospyros texana).  If the fruits have a tough outer shell, they may travel some distance from the parent plant, and if they have a soft skin, they may break open where they fall and scatter the seed or seeds within. 

Texas Persimmon, Diospyros texana

Mexican Buckeye, Ungnadia speciosa

Some plants produce very light seeds, seeds with buoyant fluff, or seeds with air trapped in them, so they can float away from the parent plant that grows in or around water, like Common Buttonbush (Cephalanthus occidentalis) or Black Willow (Salix nigra).  Others employ the assistance of animals, which can come in the form of seed or fruit eating (where the seed can pass undigested through the animal), seed caching or burying, or seed transportation.  Often unbeknownst to the animal, seeds can be covered with tiny hooks or spines that catch on a passing animal’s fur, and eventually rubbed off in another location.  Common examples include Cedar Waxwings and American Robins eating juniper and yaupon berries, both ground and tree squirrels eating and caching acorns, and many animals (including humans) that emerge from the wilds carrying the seeds of Beggarsticks (Bidens sp).    

Yaupon, Ilex vomitoria

This fall and winter, let the seeds linger! Not only do they provide much needed food for wildlife, but leaving them allows for some beautiful and mysterious patterns in your winter landscape, and the promise of renewing the cycle of life that begins again each spring!