The most profound investigation by an artist into the world of plants is Paul Klee’s “The Nature of Nature,” the second of his posthumously published two-volume Bauhaus teaching notebooks. Klee’s notebooks, the first of which is “The Thinking Eye,” are no substitute for his art. They do, however, provide entrance into the metaphors, processes, and structures of abstract painting. In “The Nature of Nature,” Klee, a cosmologist as much as a botanist, analyzes the world not to describe nature but to discover its functions, actions, and interactions. Rather than paint a bowl of fruit (a still life), Klee suggests that we consider a more comprehensive and dynamic view — an abstract picture in which we explore simultaneously “an apple tree in blossom, the roots, the rising sap, the trunk, a cross section with annual rings, the blossom, its structure, its sexual functions, the fruit, the core, and seeds. An interplay of states of growth.”

Walking through the cheekily titled “Implant,” UBS Art Gallery’s show of roughly 100 works from 1865 to the present by approximately 50 international artists, Klee is glaringly absent. Yet also absent are a host of other artists (Impressionists, anyone?) who have engaged with plants — with nature — during the last century and a half.

Certainly, we do not need yet another show of Impressionism. But “Implant,” organized by artist Jodie Vicenta Jacobson, curator at the Horticultural Society of New York (the show’s sponsor), is so narrow and seemingly random in its curatorial outlook that I began to wonder if Ms. Jacobson had much command of her subject at all. It is one thing to have a focus in a thematic show; it is another thing entirely to suggest that one’s focus is the core of one’s theme.

“Implant” does not purport to be a chronological or representative survey of artists working with plants. The show is inspired by Michael Pollan’s book “The Botany of Desire: A Plant’s-Eye View of the World,” in which the author traces the evolution of plants and their interaction with animals (including insects and humans). Mr. Pollan’s compelling, though sometimes outlandish, book, which focuses on four plants (the apple, the tulip, marijuana, and the potato), explores the well-known facts that plants and animals are interdependent, and that plants have evolved in order to attract our participation in their propagation, just as wolves, to survive — and through the domestication of humans — have evolved into dogs.

In her exhibition overview, taking the “THEY CONTROL US” view of vegetal evolution to the level of sci-fi mumbo jumbo, Ms. Jacobson asks: “Is it possible that when an artist uses plants, i.e. flower, tree, or natural landscape in a composition, the connection has been directly suggested by these presumably innocuous living things?…The plant’s authority is felt strongly over time as they compel artists to depict their history and evolution throughout artistic periods. When artists use botanical subjects in their work, it is because the plants have chosen them first. Cleverly, the plant has found a way to immortalize itself — to take eternal life in the form of an artwork.”

My favorite part of Ms. Jacobson’s supposition is the word “cleverly.” I was reminded of all those clever ways the plants made people take their own lives in M. Night Shyamalan’s film “The Happening.” However, maybe it is time for some art history — a discussion, perhaps, of the sacred and the profane in art, and an exploration of how artists engage with nature, not mimetically but metaphorically. (And while we’re at it, let’s have a reality check from the world of biochemistry.) Artists do not make art to glorify nature (despite what the plants may command them to do). They make art to glorify, to explore, their relationship with nature.

Ms. Jacobson has not chosen artists who work primarily with plants, “but artists,” she explains, “that have in a sense collaborated with plants to further a more specific idea.” I wondered, while watching Dennis Oppenheim’s “Compression-Fern (Hand)” (1970) — a looping video in which a fern is crumpled to death — or while watching Roman Signer’s “Weihnachtsbaum (Christmas Tree)” (1993) — a video of the artist hurling a tree, like a spear, off a high balcony — how, exactly, the plants benefited from the collaborations. Although I reasoned that possibly these plants were suicidal, I still questioned if “Compression-Fern” and “Christmas Tree” were, in fact, collaborations at all.

Conceptually heavy and aesthetically weak, “Implant” is an ill-conceived and poorly tended garden — if not a jungle — in which artists and ideas clash, and certain works feel so out of place that they resemble invasive species. We find Ian Campbell’s “Tongue” (2006), two five-foot-long chains made of thousands of cherry stems, tied together by the artist’s tongue; Nick Cave’s “Soundsuit” (2008), a multicolored knitted jumpsuit topped with a plant stand; Robert Gober’s “Untitled” (1998-2008), a small drawing of a topped tree in a housedress; an installation by Simon Starling in which a floral chaise lounge is juxtaposed with a photograph of a reclining nude by Henry Moore; mildly entertaining videos by Pipilotti Rist, Hiraki Sawa, and CAW + NG; cloying photographs of women, girls, and plants by Julia Margaret Cameron, Francesca Woodman, and Hellen van Meene, and photorealist renderings of plants, in paint by Carol Woodin, and in painted wood sculpture by Jim Sams.

Not everything in this show, however, needs to be weeded out. Darren Almond’s prolonged-exposure C-prints of a landscape and a waterfall, taken by full moon, are lush, as are Roe Ethridge’s pin-hole prints of flowers on floral-printed backdrops. (Yet both artists’ works suffer from their need to be backwardly innovative.) A handful of Jane Freilicher’s oil paintings of still lifes, set before windows, are not her most vibrant works of the last decade, but they pleasantly stand out in “Implant” as “other.” And a trio of Ellsworth Kelly’s large, muscularly lithe lithographs of leaves provide us with one of the few places in the show where an artist not only feels fully engaged with his subject but talented enough to bring his work to fruition. Mostly, however, the show has the disjointedly sprawling feel of an invitational in which the theme is plants.

One of the main problems with “Implant” is that its curator believes that painting, before the invention of the camera, performed mainly a slavishly “mimetic [rather than poetic] function.” This worn-out premise is extended to mean that contemporary representational art must somehow be subversive in order to be relevant. To that end, we see Susannah Hewlett’s “Untitled (Painting is Dead)” (2008), a funeral wreath that spells out its title; Peter Coffin’s “Untitled (Greenhouse)” (2002), which transforms an actual greenhouse into a performance space for musicians, and Sharon Core’s C-prints of the paintings of 19th-century American still life painter Raphaelle Peale. Ms. Core’s photographs purport to comment on the photographic nature of painting “before photography displaced painting.”

What place, you may ask, do artworks about the “death of painting” have in an exhibition about artists and plants, especially an exhibition that includes paintings? What those artworks do is to convert a show supposedly about the interaction between artists and nature into a show about the incestuous interactions between contemporary artists and art. “Implant” is really just another exhibition (in which the theme happens to be plants) of the usual subjects and their usual subversions.

Don’t miss David Melrose’s “Gesture to the Curator” (2008), which is described as a “candid art-world kiss-up.” An actual bouquet of flowers delivered weekly to Ms. Jacobson from Mr. Melrose, the curator’s husband, “Gesture,” the wall text explains, is “part institutional critique, part genuine act of love, [a] performance [that] exposes the vagaries and corruption at the heart of all selective institutional process, creative or corporate.” We cannot accuse Ms. Jacobson of nepotism, however — especially if we take this exhibition at face value and its curator at her word. In “Implant,” the artists, and possibly even the curator, know not what they do. They exist in an art world in which “the plants made me do it.”

Through October 31 (1285 Avenue of the Americas, between 51st and 52nd streets, 212-713-2885).