A plant grown from a cutting is indeed a clone. It is the actual tissue of the original plant, just grown out. Same DNA as the original plant. Only, you use clever techniques to stimulate undifferentiated cells to produce roots.
One of the linked articles, however, shows plants growing in little plastic jars. This looks like "tissue culture", which takes a plant cell sample and causes it to grow in a culture medium. But, still, it's cells from the parent plant grown out.
I don't have any of the old papers / results. But my recollection is that the Lisp workstations greatly outperformed LISP on a contemporary VAX for a given cost, in part because of the workstation's microcoded instruction set tailored to Lisp. Over time, though, commodity hardware increased significantly in relative performance simply due to the economies of scale in producing it.
You might've been able to buy a Xerox workstation for, say, $15K-$20K, while a VAX box was over $100K. BUT for a production system, the VAX could run multiple Lisp processes at the same time. (I'm guessing at costs here, it's been too long.)
Also, Richard Gabriel did a bunch of Common Lisp benchmarks, might help to look for them. (Great fellow.)
The real threat to Symbolics et al, circa 1987, was things like Gold Hill Common Lisp running on, say, a IBM PC/AT with a 286 chip and maybe a meg of memory. At, perhaps, $3,000. It ran pretty fast, the Gold Hill tech folks were very good. But GHCL had an unsophisticated development environment compared to Symbolics / Xerox.
As excellent as the workstation environments were for development, a market demands that you eventually deliver a cost effective product into customers' hands. (Or is that too much old-think?)
I worked in an expert systems company in the 80s (one mentioned in the Phillips thesis referenced in the danweinreb article). Take all this with a dose of IIRC.
As part of out work, we evaluated and benchmarked Xerox Interlisp machines, Symbolics systems, VAXen, later Gold Hill etc. to find a cost-effective delivery platform. We even eventually funded the development of a delivery-focused subset of Common Lisp.
One aspect that Symbolics didn't seem to understand back then was cost of entry and deployment: the Xerox D-machines were (IIRC) around 1/3 the cost of the Symbolics. Perhaps not as speedy, but adequate for our day-to-day development work as well as for the end customer's needs.
Symbolics had great development systems, but the delivery answers were late in coming; too late to help us.
There's lots more to be said about the late 80s collapse of AI (ES) applications and expectations, but the margins here are too small to contain it....
Apples for instance, if grown from seed, likely will not carry all the properties of the parent plant. E.g., the fruit will not taste the same.
Apple trees mostly have desirable fruit bearing tissue grafted onto plain understock.
Also, some plants show different growth characteristics in mature tissue than in young tissue, but I don't know if that applies to the redwoods.