Something strange is on display at Dumbarton Oaks.

Alongside the stately architecture and formal gardens in Georgetown lie newly acquired pieces by contemporary sculptor Charles Simonds. While Dumbarton Oaks’ museums feature august pillars, ancient black-figure vases and Byzantine mosaics, Simonds’ works represent a departure into a realm not governed by strict artistic conventions.

The sculptures are all hybridizations that refuse to submit to any single category. For example, “Head— features an oblong visage that melts into a rock-face, the boundary between human and geology far from apparent; “Tumbleweed,— a twisting white tangle, could be described either as barbed wire or as ivy.

“It’s a blurring of the distinctions between animal and vegetable and architecture,— said Gail Griffin, director of gardens.

Simonds, the son of two Vienna-trained psychotherapists, spent his formative years at the University of California, Berkeley, in the 1960s. He earned early recognition for building tiny cities — outposts of the imaginary miniscule civilization that runs throughout his work — on the canvas of his body. A case at Dumbarton Oaks displays his work alongside 15th-century depictions of humans transforming into plants, placing Simonds in the tradition of artists who explore the theme of metamorphosis.

[IMGCAP(1)]Dumbarton Oaks is well-known both for its museums containing examples of Byzantine and pre-Columbian art and its bucolic 16 acres of verdant, carefully manicured gardens. Some patrons have been distressed by the experimental nature of Simonds’ work, which seems jarring in the context of Dumbarton Oaks’ more traditional offerings.

“It’s a dichotomy, basically,— said Docent Coordinator Christine Blazina, who is exposed to visitors’ reactions during the daily tours she leads. “Some of them who are not used to seeing anything changed at Dumbarton Oaks get upset with it, but there are also those who look at it as an addition.—

The comments book in the Dumbarton Oaks museum encapsulates this ambivalence, with patrons’ reactions ranging from high praise to utter revulsion.

One entry reads, “The ugly things don’t fit in here and ruin the museum. Save them for a modern art museum or a tasteless person’s lawn.— While another enthusiastically proclaims, “The amazing work of Charles Simonds is magnificently placed in the garden so that the meaning and excitement of the art is enhanced.—

It is the juxtaposition of the old and the new, the stylized and the abstract, that makes Simonds’ pieces so provocative. Inside the museum, a case full of gleaming 5th-century to 7th-century Byzantine crosses is adjacent to Simonds’ piece “Y,— a cross made of two contorted branches that resemble swollen human limbs studded with tiny bricks.

Similarly, the offerings outside seem almost haphazard alongside the carefully planned rows of flowers. Lying on the grass near a fountain is “Stugg,— an elongated tube ending in a contorted face; “Growth— winds out of the trunk of a gnarled tree, the contrived merging into the organic.

So the reservations some of Dumbarton Oaks’ more conservative guests raise underscore the exhibition’s allure. Simonds shows that art is not static but something whose forms glide in and out of different worlds, eluding an authoritative description. If his sculptures seem alarming, then it is working.