Wildflower in Focus – Hairy Snoutbean

Rhynchosia tomentosa (Linnaeus) Hooker & Arnott Hairy (or twining) snoutbean

fter admiring the ower on the cover, you might 13,000 years ago. e Maryland Atlas shows records from have been surprised to learn its name. Hairy Calvert and Anne Arundel Counties. It is native from Maryland snoutbean? Kerry Wixted of the Wildlife south into Florida and west into Texas. Interestingly, Tennessee and and Heritage Service Kentucky are included in its range, indicat- comments, “I love the ing that it is not strictly a coastal plain common name! It does . have a hairy bean that looks like a schnoz. ;)” is issue of Mari- Hairy snoutbean is ranked S2, State reat- landica features hairy snoutbean not only ened, primarily because of habitat loss due for its beauty and its odd name, but because to conversion to agriculture, residential it’s a member of the Pea Family (), development, and timber management. and 2017 is the Maryland Native Plant According to the Conservation/Ecology Society’s Year of the Pea. note in the RTE list, “this species quickly responded to prescribed re management at THE PEA FAMILY one site, appearing robustly in the new e peas comprise the third largest plant habitat (apparently from the seed bed).” family (after the asters and the orchids), (See the article on page 5 to learn about the with over 20,000 species worldwide. Mary- RTE List.) land Plant Atlas lists 42 genera and 122 species present in Maryland, some herba- One reason why Maryland has so many rare ceous and some woody, some native and is that it is located at the southern end some exotic. Using the snoutbean as an of northern ecosystems and at the northern example, let’s look at the characteristics end of southern ecosystems. Hairy snout- typical of the Pea Family. Encountering this bean is an example of this phenomenon; plant for the rst time, how would you Maryland is at the northern periphery of its know it’s a pea? It has a square stem and an range. If a species is doing ne in other irregular ower. Could it be a mint? Nope. areas, why bother to preserve it in Mary- e leaves are alternate, not opposite like land? In fact, conserving peripheral popula-

mints. e ower looks just like a butter y. Kerry Wixted tions can be especially important. is is And the leaves are trifoliate. So it must be a pea. because peripheral populations often (Linnaeus) diverge genetically from central populations Not visible to the eye is another characteristic of most Pea Family as a result of isolation, genetic drift, and natural selection. e members—their ability to x nitrogen in the soil. is ability is not survival of species may depend upon the existence of genetically unique to the Pea Family, as it is shared by a few members of other distinct populations that can thrive under changing conditions. (See, plant families. Nitrogen xation is an elegant example of the interac- e.g., P. Lesica and F.W. Allendorf. 1995. When Are Peripheral Popula- tion and interdependence of dierent organisms. Because nitrogen is tions Valuable for Conservation? Conservation Biology 9:753-760.) a component of protein, all plants and animals need it for survival, ~ Kirsten Johnson and they need it in a biologically accessible form; they can’t take it from the air. Nitrogen-xing plants and other organisms provide the Pea Family Visible Characteristics solution by synthesizing usable • Leaves alternate and stipulate. nitrogen compounds. Mean- • Flowers papilionaceous (shaped like a butterfly), in racemes, while, the nitrogen-xation in spikes or heads. plants like the peas is actually • 5 sepals, usually forming a short basal tube. accomplished by symbiotic • Compound leaves, often trifoliate. bacteria in root nodules—not by • Petiole and petiolules with swollen bases the plant tissue itself. • Fruit a legume

HAIRY SNOUTBEAN Hairy Snoutbean can be found Pictured Left: Rhynchosia tomentosa. USDA-NRCS PLANTS Data- growing on Maryland’s Eastern base/ Britton, NL, and A Brown. 1913. An illustrated ora of the Shore, on ancient, low, pine-covered sand northern United States, Canada and the British Possessions. 3 vols. dunes that were formed between 30,000 and Charles Scribner's Sons, New York. Vol. 2: 422.

Marilandica Spring 2017 page 2