Native Spaces | Twisted Taxonomy, Rare SF Manzanitas

ROSEI Nobody can agree on what to call the rare manzanitas of San Francisco.

Quoth Mike Vasey, co-author of the new treatment for Arctostaphylos in the Jepson Manual's 2nd editon:

"I think there's a bit of an irony with rosei that might be worth talking about. It was originally described from the Lake Merced area as A. roseii by Alice Eastwood in 1933. Later, Howard McMinn recognized its affinity with A. crustacea and described it as A. c. var. rosei, still noting that it "is limited in its distribution to the hills bordering Lake Merced, San Francisco, California". In 1964, Jim Roof wrote an article in Four Seasons in which he reported A. c. var. rosei occurring along the immediate coast along Big Sur in Monterey from Plaskett Creek through Yankee Point. He later (1966) extended its distribution to Arroyo de los Chinos on the Hearst Ranch in San Luis Obispo. Based on these observations by Roof, A. c. var roseii suddenly went from being a highly localized endemic of San Francisco to a more widespread entity (albeit restricted to the immediate coast) ranging from San Francisco to San Luis Obispo.

"In 1968, Wells did away with the "variety" rank in Arctostaphylos and made everything either a subspecies or forma. At the same time he combined two complexes of burl sprouting, tetraploid, bifacial (leaves with different surfaces, usually lacking stomata on the upper surface) manzanitas into A. tomentosa. A. crustacea var. rosei thus became A. tomentosa ssp. rosei. The most prominent difference between the A. tomentosa and A. crustacea complexes is that A. tomentosa is characterized by grey, shreddy bark whereas A. crustacea typically has smooth, red bark.

"Are you with me so far (I know this is a bit mind numbing)? Now's when the plot gets interesting."

"I have been working with Tom Parker for the past 15 years on Arctostaphylos and this coming year we will putting out two treatments on this genus, one for the 2nd Edition of the Jepson Manual and the other for the multi-volume Flora of North America. Tom and I believe that the Wells conception of the A. tomentosa complex is too unwieldy and we will be going back to a modification of the previous treatment by recognizing a smooth, red barked complex (A. crustacea) and a grey, shreddy barked complex (A. tomentosa). Thus, A. tomentosa ssp. rosei will become A. crustacea ssp. rosei.

"There is only one complication: A. crustacea ssp. rosei is the only representative of the A. crustacea complex that has somewhat persistent, shreddy, red bark; i.e. it is a bit intermediate between the A. tomentosa complex and the A. crustacea complex. So, it is a bit odd. Further, I'm not so sure how this bark character holds up with the so-called A. crustacea ssp. rosei populations along the Santa Lucia coast. Are these really the same as the San Francisco A. crustacea ssp. rosei? We still don't know for sure. All we really know is that they are clearly closely related and that the hair patterns that distinguish the various subspecies in the A. crustacea complex are variable, even within populations (i.e. why we have the hair type of A. crustacea ssp. crustacea in the same population as A. crustacea ssp. rosei).

"So, because of this character variability - especially in a fairly wide-ranging tetraploid complex like A. crustacea - it is really impossible to say that the Lake Merced A. c. rosei is not genetically distinct from the Santa Lucia coastal A. c. rosei (and our molecular genetic work so far is not fine-grained enough to address this question). If it is genetically distinct, the Lake Merced A. c. rosei entity is highly endangered, on a par with A. hookeri ravenii (another one we're changing but that's for another time), since it consists of only two individuals in the wild that I know of. The irony I mention is simply that Jim Roof, a great lover of endemic manzanitas (he named a few up on San Bruno Mountain) started a process which resulted in the Lake Merced manzanita being overlooked for official protective status. Maybe he was right, maybe not. Under the Endangered Species Act, recognizably distinct population segments (at least of animals) are given protection. I would argue that a prudent course for the Lake Merced A. crustacea rosei would be to give it similar recognition and protection. However, I actually have never made that argument in writing until this moment!"
-Mike Vasey, 2006.08.16

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photos by Paul Furman

Posted by: Paul Furman | November 8, 2007 11:46 AM



Twisted Taxonomy, Rare SF Manzanitas Nobody can agree on what to call the rare manzanitas of San Francisco. Quoth Mike Vasey, co-author of the new treatment for Arctostaphylos in the Jepson Manual's 2nd editon: "I think there's a bit of an irony with rosei that might be worth talking about. It was originally described from the Lake Merced area as A. roseii by Alice Eastwood in 1933. Later, Howard McMinn recognized its affinity with A. crustacea and described it as A. c. var. rosei, still noting that it "is limited in its distribution to the hills bordering Lake Merced, San Francisco, California". In 1964, Jim Roof wrote an article in Four Seasons in which he reported A. c. var. rosei occurring along the immediate coast along Big Sur in Monterey from Plaskett Creek through Yankee Point. He later (1966) extended its distribution to Arroyo de los Chinos on the Hearst Ranch in San Luis Obispo. Based on these observations by Roof, A. c. var roseii suddenly went from being a highly localized endemic of San Francisco to a more widespread entity (albeit restricted to the immediate coast) ranging from San Francisco to San Luis Obispo. "In 1968, Wells did away with the "variety" rank in Arctostaphylos and made everything either a subspecies or forma. At the same time he combined two complexes of burl sprouting, tetraploid, bifacial (leaves with different surfaces, usually lacking stomata on the upper surface) manzanitas into A. tomentosa. A. crustacea var. rosei thus became A. tomentosa ssp. rosei. The most prominent difference between the A. tomentosa and A. crustacea complexes is that A. tomentosa is characterized by grey, shreddy bark whereas A. crustacea typically has smooth, red bark. "Are you with me so far (I know this is a bit mind numbing)? Now's when the plot gets interesting." "I have been working with Tom Parker for the past 15 years on Arctostaphylos and this coming year we will putting out two treatments on this genus, one for the 2nd Edition of the Jepson Manual and the other for the multi-volume Flora of North America. Tom and I believe that the Wells conception of the A. tomentosa complex is too unwieldy and we will be going back to a modification of the previous treatment by recognizing a smooth, red barked complex (A. crustacea) and a grey, shreddy barked complex (A. tomentosa). Thus, A. tomentosa ssp. rosei will become A. crustacea ssp. rosei. "There is only one complication: A. crustacea ssp. rosei is the only representative of the A. crustacea complex that has somewhat persistent, shreddy, red bark; i.e. it is a bit intermediate between the A. tomentosa complex and the A. crustacea complex. So, it is a bit odd. Further, I'm not so sure how this bark character holds up with the so-called A. crustacea ssp. rosei populations along the Santa Lucia coast. Are these really the same as the San Francisco A. crustacea ssp. rosei? We still don't know for sure. All we really know is that they are clearly closely related and that the hair patterns that distinguish the various subspecies in the A. crustacea complex are variable, even within populations (i.e. why we have the hair type of A. crustacea ssp. crustacea in the same population as A. crustacea ssp. rosei). "So, because of this character variability - especially in a fairly wide-ranging tetraploid complex like A. crustacea - it is really impossible to say that the Lake Merced A. c. rosei is not genetically distinct from the Santa Lucia coastal A. c. rosei (and our molecular genetic work so far is not fine-grained enough to address this question). If it is genetically distinct, the Lake Merced A. c. rosei entity is highly endangered, on a par with A. hookeri ravenii (another one we're changing but that's for another time), since it consists of only two individuals in the wild that I know of. The irony I mention is simply that Jim Roof, a great lover of endemic manzanitas (he named a few up on San Bruno Mountain) started a process which resulted in the Lake Merced manzanita being overlooked for official protective status. Maybe he was right, maybe not. Under the Endangered Species Act, recognizably distinct population segments (at least of animals) are given protection. I would argue that a prudent course for the Lake Merced A. crustacea rosei would be to give it similar recognition and protection. However, I actually have never made that argument in writing until this moment!" -Mike Vasey, 2006.08.16 Posted by Geoffrey Coffey on August 16, 2006 01:21 PM \| Comments photos by Paul Furman Posted by: Paul Furman \| November 8, 2007 11:46 AM Post a comment (If you haven't left a comment here before, you may need to be approved by the site owner before your comment will appear. Until then, it won't appear on the entry. Thanks for waiting.) Name: Email Address: URL: Remember personal info? Comments: (you may use HTML tags for style)

Twisted Taxonomy, Rare SF Manzanitas

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