Discovered in 1963 by Ernest Twisselmann, Nemacladus twisselmannii J.T.Howell has been known from only two localities on the Kern Plateau, totaling about 400 individuals in a 10 acre area. A new population was discovered in April 2012, in Culp Valley, Anza Borrego Desert State Park, Riverside County, a disjunction of about 350 km. The group who made the original discovery surveyed and mapped 53 plants in 2012, most in an active wash and a few in a side wash. In 2013, 23 plants were found in the original location (five in the active wash, 18 in the side wash). The type locality was considerably disturbed due to foot traffic of firefighters battling the Vallecito Fire in August 2012. Similar habitats nearby were surveyed in 2012 and 2013, but no other plants were found; however, in April, 2019, about 30 plants were found in the original location. The significant geographical disjunction and presence of some notable morphological differences warrants recognition of this new population as a separate variety.

Nemacladus twisselmannii var. botanywomaniae differs from var. twisselmannii in having the flower non-resupinate, sepals broadly deltate, and occurrence in desert habitat. The term "resupinate" refers to flowers that are turned upside down during development, such as most orchids and some Nemacladus species. By the way, this variety was named to commemorate a female, in which case the epithet should end in "iae" not "ei" or "ii" in compliance with Article 60.12 of the ICN (Mcneill et al., 2012). According to Pronunciation of Biological Latin by Peter Ommundsen (accessed 9 June 2020) the correct pronunciation for this commemorative name (eponym) would be botanywoMAN-ee-ee. If it commemorated a male that preferred the name botanyman it would end in ii and be pronounced botanyMAN-ee-eye. I was taught to pronounce all of the vowels by Dr. Carl Sharsmith in his alpine & subalpine botany courses at Tuolumne Meadows, Sequoia National Park. Another botany professor just told me to just pronounce scientific names with authority!

Distribution and ecology: Anza Borrego Desert State Park, in desert washes at 1200 m. Known only from the type locality. Nemacladus species are commonly called threadstem and the plants are commonly used by hummingbirds for nest-building. The flowers are minute; however, in some species (N. rubescens) they resemble miniature orchids.

Etymology. The variety is named for Kate Harper, Senior Consulting Botanist and Wildlife Biologist, Harper Biological Consulting, who saw the plants first. She has been part of a group that has been documenting the plants of Anza Borrego Desert State Park for many years. When advised that the authors wished to name the plant for her in recognition of her discovery, she requested that the epithet be the name by which she is known in the group, which is "Botany Woman." In keeping with the common name for this genus, and to avoid confusion with Ernest Twisselmann's variety on the Kern Plateau north of Lake Isabella, the name "Botany Woman's Threadstem" was selected.