Another Name Bites The Dust

Day 229: As of this writing, you may still refer to Aphyllon purpureum by its synonym Orobanche uniflora, but at the rate Latin binomials are being revised, that terminology may change by the time I hit the "post" button. I'm trying to keep up, honest I am, but there are moments when I just want to reach out through the ether to throttle the first taxonomist I can lay my hands on. ITIS (Integrated Taxonomic Information System) still lists it as Orobanche, but I happen to know that my contact at the Burke Museum has more up-to-date sources. Burke puts it under Aphyllon purpureum, and I accept their authority.

In any event, this lovely flower has no foliage. The leaves you see in the photo belong to Suksdorfia ranunculifolia (I checked...that nomenclature is current, and the plant will be the subject of a future post). While Oroba...dammit...Aphyllon frequently grows in the same environments, it is parasitic on several different species of sedum (small succulents, specifically S. oreganum and S. divergens in Mount Rainier National Park). It draws nutrients from its host and cannot exist independent of it. Research is being done to determine if the relationship goes two ways, but current studies do not indicate any benefit to the sedum. It is also parasitic on some members of the pea family, hence its common name "Naked Broomrape." "Broom" refers to the legumes (think "Scotch broom") and "rape" comes from Latin "rapum," meaning "a tuber."

Broomrape And Monkeyflower

Day 234: Another of Team Biota's recent finds: a new location for Naked Broomrape (Orobanche uniflora). This uncommon species is parasitic on at least two sedums and some saxifrages in Mount Rainier National Park; the unidentified host is concealed by the lush Suksdorfia foliage in this image. Broomrape stems are devoid of foliage; the plant contains no chlorophyll and is entirely dependent on the nutrients it pulls from its host (i.e., it is a "holoparasite"). Invariably, when I refer to this plant by its common name, it provokes a negative reaction. In fact, the Latin word "rapum" refers to a tuber, and "broom" refers to the family of vetches (legumes),, another common host for the Orobanche genus. And just to demonstrate that science doesn't rule every single moment of my life (close, but not total), the photographer in me could not resist including that sweet, smiling little Monkeyflower (Erythranthe alsinoides) to top off the visual line.

Naked Broomrape On Sedum

Day 236: Orobanche uniflora is a trickster. Don't assume that the succulent foliage at its base belongs to the same plant. It does not. In fact, you will find Naked Broomrape in association with at least two different leaf-forms in the Park. This beautiful little plant is parasitic on the roots of a number of different sedums. The leaf rosettes of two of the most common are shown in this photo (S. divergens at the bottom, S. oreganum to the right of the flowers). Because Orobanche lacks chlorophyll and cannot photosynthesize on its own, it takes its nutrients from its host; whether or not it contributes anything to the relationship with sedum is at this point conjectural.

Orobanche In A Bunch

Day 237: You might be misled into thinking those pretty lavender flowers belonged to the succulent leaves beneath them, but in fact, there's something botanically sinister going on here. Orobanche uniflora (Naked Broomrape) is a parasite with a particular appetite for the roots of saxifrages and sedums. The species lacks chlorophyll and is therefore incapable of photosynthesis, so it relies on host plants to process nutrients into a form it can utilize. There are several categories of parasitism in the realm of botany. Broomrape is considered a holoparasite, i.e., one which depends entirely upon the host.