CENTRAL SPINE NEWSLETTER OF THE CE N TRAL ARIZO N A CA C TUS & SU cc ULE N T SO C IETY AN AFFILI A TE OF THE Cac TUS & SU cc ULENT SO C IETY OF AMERI ca ON THE WEB A T www .C ENTR A L A RIZON acac TUS .ORG October, 2008 IN THIS ISSUE: • Mammillaria and Mathematics - Michael Newberry • A Crash Course on Winter-Growing Bulbs - Celeste Gornick • The Perfect Potting Mix for Cacti and SucculentsTom - Gatz • Proposed Updated By-laws of the Central Arizona Cactus and Succulent Society (CACSS) 2008 CACSS OFFI C ERS President: Steve Plath ................................ 623-238-3342 There is no [email protected] OCTOBER SPEAKER Vice-President: Lee Brownson ............... 480-951-4945 instead we have our [email protected] Secretary: Julie Plath .................................. 623-915-7615 CACSS October Auction Event [email protected] Treasurer: Wayne Whipple ..................... 480-460-3623 When: October 26th, 2:00 pm [email protected] Where: Dorrance Hall Set-up will start at 12:00 noon BOARD OF DIRE C TORS TERMS ENDING 12/2008 LO C AL CALE N DAR Gard Roper .................................................... 602-996-9745 th [email protected] October 26 , Sunday, 12 pm Setup, 2 pm Auction Daniel Sumberg ........................................... 480-361-6503 Silent Auction of Members’ Plants [email protected] Dorrance Hall, Desert Botanical Garden Ingrid Swenson ............................................ 602-957-9865 rd [email protected] November 23 , Sunday, 2 pm Speaker - Ernesto Sandoval TERMS ENDING 12/2009 Title - Doug Dawson ............................................... 480-893-1207 Baja California: A Natural History from the Land doug.dawson@ of Boojums and Cardons gcmail.maricopa.edu Regular Club Meeting Leo Martin .................................................... 602-852-9714 Dorrance Hall, Desert Botanical Garden [email protected] December 7th, Sunday, Noon Steve Martinez ............................................. 602-688-4339 Party and General Membership Meeting. Start your holiday [email protected] Cynthia Robinson ....................................... 602-615-2261 season by attending the CACSS Annual Holiday Party. It is [email protected] great fun and the food (Pot-luck) is always wonderful. It is a Lois Schneberger ..........................................480-946-8373 great time to meet other members of the society while elect- [email protected] ing next years’ leadership team. This event is held at Webster Auditorium at the DBG. 2008 CACSS COMMITTEES Programs & Workshops ............................ Lee Brownson Publications & Publicity ............................ Cynthia Robinson Newsletter Editor ........................................ Laurence Garvie [email protected] Assistant Editor ........................................ Paul Schueneman 480-706-1672 [email protected] Membership .................................................. Doug Dawson or Jo Davis 480-839-3792 Finance ............................................................ Wayne Whipple Plant Rescue .................................................. Robert&Cheryl Brown 480-664-9409 [email protected] Library ............................................................. Erik Anderson 480-967-3984 ON THE COVER woodcraftman@ A beautiful Pereskia grandifolia ssp. violacea. Few plant enthusi- earthlink.net asts grow Pereskia in the Phoenix area but they can be rewarding 2009 Show ...................................................... Cynthia Robinson plants in that some species are easy to grow and flower throughout the year. Taxa of the Pereskia display many primitive characteris- 2009 Sale ........................................................ Mike Cone tics thought to have been inherited from the first cacti, such as 623-215-7692 persistent non-succulent leaves and the lack of fleshy or succulent [email protected] stems. Despite their primitive features they bear the distinctive Refreshments ................................................ Melinda Louise spine-bearing areoles characteristic of cacti. Hence, the genus is Field Trips ...................................................... Daniel Sumberg or regarded as the ancestor of the modern family Cactaceae. There Lois Schneberger are currently 17 species ofPereskia . By-Laws ........................................................... Lois Schneberger Photo © Michael Newberry, www.michael-newberry.com Web-Site ......................................................... Lee Brownson Publication of material in the Central Spine does not imply agreement with the ideas expressed therin by any portion of the membership of the CACSS, nor does it constitute an endorsement or support for any portion of such material by the CACSS, or the Central Spine, regardless of any position or office held by the author. All such material represents a comment and/or personal opinion of the author. 2 CENTRAL SPINE October, 2008 PRESIDENT’S LETTER It’s Auction time! This month we’ll have our big annual e-mail or mail-in ballot, which will be included in the Silent Auction instead of a regular meeting; which will November issue of the Central Spine. I want to thank be in Dorrance Hall at the Desert Botanical Garden on Lois and her committee for the incredible time (and Sunday, October 26th. Set-up will start at 12:00 noon so patience with the Board) she has put into bringing us please bring in those yummy plants early then at 2:00 this document. pm we’ll start the auction. Lee Brownson has offered to be MC so it promises to be a fun time and a great way As mentioned at the September meeting the DBG will to get some unique and desirable specimens. I hope we be holding a special art exhibit throughout the garden see lots of members come out and support the club! presented by Chihuly. Because of this event the DBG will be restricting the number of people going through In this issue you’ll see the modified By-laws provided the garden within specified time slots. For CACSS by the By-laws Committee led by Lois Schneberger. It members we will have access, at no charge, to attend has been a long process to evolve and update the By- our regular monthly meetings. At the main entrance to laws, which began last year. Early this month the Board the Garden there will be a Private Event Booth where voted to approve the new By-laws, which now go to the you’ll get your ticket/wrist band to enter. Also there’s General Membership for vote. They are published in been concern how the Chihuly event will impact our this issue of the Central Spine and the November issue ability to conduct our spring show and sale in typical so everyone will have ample time to review and com- fashion. At a recent meeting between several CACSS pare them to the existing By-laws. At the November Board Members, myself, and Jane Schlafly of the DBG meeting we’ll reserve a short period during the General we found that there will be minimal impact and the Meeting to address comments from the floor. At the show will go on as scheduled March 11th through 15th. December meeting the General Membership will have the opportunity to vote on the new By-laws. Those See you at the meeting! - Steve Plath unable to attend that meeting will be able to vote by 3 CENTRAL SPINE october, 2008 Mammillaria and Mathematics Michael Newberry Tucson, Arizona, www.mammillarias.org th ook closely at any species in the genus Mammillaria 5, 8, 13, 21, 34, and so on. For example, the 7 and 8th numbers and you’ll see something special about the arrangement are 3+5=8 and 5+8=13. In almost all Mammillaria, the number of tubercles and spines: they are aligned in spiral arcs of spiral arcs wrapping in opposite directions are adjacent num- that wind bers of the Fibonacci Series. The more tightly wound spiral is Loutward from the more difficult to trace and always has the lower number. There- meristem (growing fore, you can determine the Fibonacci pair simply by counting point) at the stem’s the number of spiral arcs which run most radially outward or apex. Looking at most parallel to the stem (see the illustration below). If this is 13, the plants pictured then the Fibonacci pair is 8/13. here, you can see two sets of spirals: There are only four Fibonacci pairs represented in the genus one wrapping Mammillaria: 5/8, 8/13, 13/21, and 21/34, with the middle two pairs clockwise and being most common. For example, M. melanocentra and M. the other, meet- winterae both have ing it almost at a 8/13 counts while M. right angle, wrapping counter clockwise. These specimens show sempervivi and M. exemplary spirals; in some species, like Mammillaria elongata, M. chioncephala both surculosa, or M. plumosa, the spirals may vague or hidden, but have 13/21 counts. they’re still present. It is a remarkable fact that these spiral pat- Just as for flower terns aren’t just arranged in a haphazard way but, instead, follow color and central a very particular mathematical rule specific to a given species. As spine count, the a result, the number of clockwise and counter clockwise spirals spiral count is not can be used along with other characters, like flower color or absolutely constant central spine count, to key the species of Mammillaria. within a species, and a rare speci- The spiral pattern pres- men may be found ent in Mammillaria, as in which the count well as in other plant is the next higher pair or does not even form a Fibonacci pair. structures, follows a rule However, finding an occasional specimen with a non-Fibonacci known as the “Fibonacci pair, like 16/25, does not invalidate spiral count as a taxonomic th Series”, after the 12 character any more than does, say, finding a Mammillaria magni- century mathematician mamma with yellow, rather than red flowers. Fibonacci. The Fibonacci Series is a sequence of The best genus-wide discussion of spiral counts in Mammillaria numbers in which each can be found in Robert T. Craig’s “The Mammillaria Hand- number is the sum of the book” (1945) in which Craig included spiral count in his species previous two. Starting descriptions. No one has found Craig’s spiral counts less reliable with 0 and 1, the Fibo- than other taxonomic characters, yet spiral counts have been nacci series is 0, 1, 1, 2, 3, ... continued on next page ..