The lanky man with dirt-caked gardener’s hands and the twinge of a Texas drawl points to a small round nub at the base of a potted flower.
“See this?” He leans down in the muted light of the greenhouse, rubs it gently with his thumb. “New growth.”
Giving the unbloomed orchid an approving look, he nods. “Look at that growth. That’s healthy.”
As far as Jim Marchand, 63, is concerned, orchids are the “ultimate plant obsession.” The Hopkinton resident and Texas native has been collecting, cultivating, and hybridizing the elegant, diverse, and vibrantly colorful family of flowers for nearly 20 years.
And now, he has a whole lot more to care for: He recently came into possession of one of the area’s most prized private orchid collections. Formerly owned by Victor DeRosa, who in his late 80s has retired and recently moved to Florida, the flowers are what remain of what was once one of the most successful cut flower businesses in the Northeast, DeRosa Florist in Natick.
The collection includes roughly 400 hybrid cat- tleyas, members of a prolific genus known for its variety of colors and large blooms (as well as its long-held position at the center of corsages); several dozen Paphiopedilum examples (most commonly known as lady’s slippers, featuring wild, unusual, and often spotted flowers); and a handful of other genera.
Most of the plants, which are housed at a private estate in the area, will be transferred to a greenhouse on Marchand’s property sometime this summer. He will sell off the duplicates.
Marchand purchased the collection last September, but declined to say how much he paid, noting that it has much more than monetary value. DeRosa was not available to be interviewed for this article.
“They talk about that orchid obsession,” said Marchand, an assistant professor and researcher in the anatomy and cellular biology department at Tufts University who left his hometown of Houston more than 25 years ago. “I’ve got it.”
As, said Marchand, does DeRosa, an old friend who sold Marchand his first orchid decades ago, and who entrusted the collection to him with the express purpose of keeping it largely intact.
“He still thinks of it as his,” Marchand said. “It’s his love.”
After emigrating from Italy in the midst of the Depression, DeRosa started his business in 1941, according to past Globe stories. His biggest business was in cut orchids and corsages. For decades, according to Marchand, DeRosa controlled the Northeast orchid market, and won top awards for his plants from the Massachusetts Orchid Society and the American Orchid Society.
But the game changed in the 1990s, when competition started coming from overseas, and orchids could be had for much lower prices at home improvement and department stores.
When things were going well, the collection was five times its current size; but DeRosa whittled it down over the years, keeping the prize-winners and his personal favorites, Marchand said. In a 2001 interview, DeRosa told the Globe he had 25,000 orchid plants in many varieties that he started from seed, cloned in his Natick lab, and sent in bottles to be grown in Hilo, Hawaii.
“These are the special ones that Victor’s collected over 30 to 40 years,” Marchand said of his new collection. “Some are unique. No one else has them.”
Sheer diversity is one of the hallmarks of the orchid, according to expert William Cullina, author of “Understanding Orchids.” No one knows how many varieties there are, he said, with new ones are being discovered all the time, but he put the ballpark figure as 25,000 to 35,000 species.
“You never run out of orchids, there are always new ones,” said Cullina, who lives on Southport Island in Maine. He also described an “elegance and sophistication” that are not found in other flowers. “There’s an almost infinite variety of form and color and size. For a collector, it’s perfect.”
Marchand certainly feels that way. His first green-thumbing was crossbreeding rhododendrons; when he tired of that, he moved on to orchids, which he called the most highly evolved flower, and also the most difficult to grow, requiring a perfect amount of water and sun exposure.
But, he noted, “they’re immortal, as long as you take care of them.”
Ultimately, DeRosa’s collection will accentuate Marchand’s own assemblage of a few hundred flowers, his favorite being the lady’s slippers, which he likes for their “weird” look.
“These orchids are part of Victor,” Marchand said as he stood in the greenhouse housing them. But after 15 or 20 years watching his friend cultivate them, seeing them bloom, he added, “the collection has become part of my life, too.”
The potted orchids sat all around in various levels of rows; none were in bloom. Patches of clover grew in pots with some of them; others had outgrown their confines, their spaghetti-like roots hanging out in tangled protrusions.
Marchand walked around to inspect them, rubbing his fingers over their thick leaves, testing the dampness of their soil. As he worked, he explained that the collection has its biggest bloom in winter, although it can bloom all year round, lasting anywhere from three weeks to three months.
Many of them, though, he has never even seen bloom. And, because most of the flowers are not labeled — DeRosa was so familiar with them that he could tell what they were just by looking at their foliage — Marchand doesn’t know what many of them are.
“There are some beauties I haven’t seen bloomed,” he said. “It’s a big mystery.”
Twisting a dead leaf off a plant, he shrugged. “They all need work.”
He noted that some were recently infected by scale insects; he sprayed them with insecticide. He will eventually repot all of them, and divide others that have overgrown their pots.
He pulled one off a shelf, carrying it to a work table that was a bramble of tipped pots, clippers, scoops, and screwdrivers. Leaves lay scattered on the floor, blown in from outside through the open entryway.
He set to work on dividing the flower, removing it from its pot, cutting off its dead roots, then repotting it with a mulch-like mixture, broken clay bits, and foam pieces that aid with oxygen and drainage.
“It’s very peaceful, having your hands on plants,’’ Marchand said.
“This is why I do it.’’
Taryn Plumb can be reached at firstname.lastname@example.org.