Our current batch of Aloe polyphylla Seed were harvested from exceptional specimens and stored at refrigerator temperature. It is hybrid seed produced by hand pollination of differing genotypic parents.
1. When will it spiral like the photos on your website?
2. My plant has yellow leaves with brown tips. Why ?
3. When do I water it?
4. How large a pot should I use?
5. When do I fertilize it?
6. My plant has collapsed and shrunk, and the rosette has closed up. What can be done to save it?
Visit our YouTube Channel for more vidoes!
Alan C Beverly - Spring 2023
The reproduction of Aloe polyphylla, an endangered species I introduced to the nursery industry back in 1991, is difficult because in the genus Aloe you must have a stem section to root. For this basal rosette form there is effectively no stem, there is no meristem on any leaf which can be coaxed into developing. You must have seed . For A.p. only adult plants (> 150 leaf) will flower in the Spring, and may not repeat again the next year. This makes seed rather precious. In the first 35 years of my involvement with A.p. I was not able to produce much seed, and many germination trials gave poor results. I have since been able to breed hybrid seed by the thousands because I had mature plants to create hybrids, and found the correct seed germination formula. The pollination biology favors outcrossing , but selfed seed is viable.
Nurserymen, wowed by the architectural form of this species, were frustrated by this propagation challenge and turned to tissue culture for results which I show here are disappointing . The science of tissue culture is well understood, worked out by Abrie & Van Staden (1) , and the nursery industry has successfully applied this technique to many species in their quest to produce plants which could drive sales. Nobody suspected that the results I reveal here for A.p. would be so disappointing.
The first 7 years of A.p. TC ( tissue culture) plants’ life are nothing exciting because the visual sense of 5 spiral rows of sequenced leaf is confused and disorganized and depends on the plant reaching the ~45 leaf stage. These TC plants only reward a new owner with a visual spiral pattern in the 8th year. These plants require more development time than a seed grown plant ,which shows spiral growth pattern in the second year. I can raise a 65 leaf plant from seed in two years and it shows either a Right, or Left spiral orientation. Photo A shows a correct sequence on an adult (~150 leaf) plant.
Clones obtained from a local grower were cultivated for several years and planted into the landscape in a sandy, well drained soil. The photos B,C,D show plants about 15” diameter and about the 75+ leaf stage with abnormal, confused leaf sequence difficult to describe. These plants have not been able to form spirals we witness in seed grown plants which divide in a specific way in space and time to produce the spiral sequence normal to seed grown plants. A seed embryo comes equipped and organized to produce the recognizable pattern on day one of its life. I have seen wild plants and in my nursery change growth orientation from R to L ,and L to R . They look strange , but are not confused. There is thus NO genetic prescription to the growth orientation of any plant . New leaf emerge from the center as older leaf , appressed to the soil and shaded , are resorbed . In this way the plant continuously re-invents itself.The service life of a single leaf in an adult plant (~150 leaf) is 2-3 years . The developmental dynamics of the apical meristem cell are fickle, and vulnerable to perturbations . I never saw any confused leaf sequences in any wild plants, nor in any of my nursery plants. An adult plant will sometimes undergo binary fission, which then requires 2-3 years for the two plants (identical genotypes) to grow apart. I have witnessed this many times in nursery plants. Sometimes small “pup” plants will emerge from below . Not enough to use for propagation.
Spiral phyllotaxy is common in the plant kingdom. There are invertebrates species that also find the Fibonacci series a solution to their body plan. The explanation is still held secret by an embryo cell , and the exacting sequence of events and how the controls work remains a mystery to biologists. Siobhan and Kuhlemeier (2) reviewed how plants develop leaf and have offered insight into the A.p. clone dilemma. The first cell division of an embryo in a germinating seed established root-shoot polarity. Then subsequent cell divisions establish the proto-tissue of each. Differentiation of cells begins to designate their future function. A general principle in botany is that all plant cells are totipotent, that any cell has the ability to develop into another whole plant. In tissue culture cells are not organized as in a seed embryo, and are slower to develop. That TC plants still eventually develop into whole plants is one of biology’s unsolved mysteries.
“How this early embryo forms itself into an organized entity has long been considered by many to be taxonomically significant “ (Lersten, 3)
Many researchers have wondered how to discover the answers but there is little to report. We know that genes are a blueprint for synthesis of specific proteins , but do not act as directors of organogenesis. It is achieved by macromolecular self assembly from the bottom up.as opposed to from the top down. This gap in embryology is so profound that Dawkins (4) has underscored it in a discussion of how organogenesis occurs. Siobhan & Kuhlemeier (2) discuss gradients of hormone signals in varying ratios to accomplish specific cell function and leaf development . Other researchers have focused on using genetic mutants (5,6) to learn how it happens in Arabidopsis.
Whatever plant biologists decide about organogenesis I am sure that seed grown A.p. have an advantage over TC plants . I pledge to continue the effort to produce genetic recombinants to help save this wonderful, amazing endangered species
1. Abrie,A.L. & Van Staden Jan 2001 Plant Growth Regulation 33 (1):19-23 “Micropropagation of the Endangered Aloe polyphylla”
2. Siobhan,A. & Cris Kuhlemeier 2010 The Plant Cell vol 22 : 1006-1018 “How A Plant Builds Leaves”
3. Lersten, Nels Flowering Plant Embryology Blackwell 2004
4. Dawkins , Richard The Greatest Show On Earth pg214-218
5. S. Shannon & D.Ry Meeks-Wahner 1991 The Plant Cell vol 3: 877-892 “A Mutation In The Arabidopsis Gene TFL 1 Affects Inflorescence Development”
6. S. Shannon & D.Ry Meeks-Wagner 1993 The Plant Cell vol639-655 “ Genetic Interactions That Regulate Inflorescence Development In Arabidopsis “
Reproduction of this species is nearly impossible via the commontechnique taking stem cuttings because of the acaulescent habit.For all other caulescent species in the genus this is easy to do. Yeteven this method produces only a few plants. Seed germination isjust as difficult because plants rarely flower and the pollinationbiology is set up to produce outcrossing only, with maturation ofanthers and stigmas separated in space and time .Two plants ofdiffering genotype flowering synchronously are needed to producehybrid seed .This is again a great restriction for any growerwishing to produce hundreds of spiral aloes.
Some individuals have developed tissue culture techniqueswhich also have a downside. This photo shows a 5 year old t.c.plant with a confused leaf sequence. In year 8 these plantscorrected themselves ! Real seedling have no such handicap.Tissue culture cannot become the preferred method of reproductionbecause of this factor. The preservation of any endangered species rests on increasing the genetic diversity. Cloning can not satisfy this.
The pollination biology creates hybrid seed almost exclusively. These photos show the developing inflorescence . The first flower to open is on the bottom row, and the anthesis (the sequential opening of single flowers) proceeds to the uppermost flowers. The erect unopened flowers fall pendulous and the anthers are elongated first and then release pollen. The nectaries at the base then release nectar for the Malachite Sunbird’s pollination services. After the anthers have dehisced the style is elongated ,the stigma protrudes beyond the corolla lip and becomes receptive. Each flower may produce 51 seeds from 3 locules of 17 embryos each when pollinated. After pollination the pendulous flower stands upright as the seed matures ! The epidermis of the seed capsule has fully functional chlorophyll.
Thanks for your business and interest in Aloe polyphylla. Here is a brief set of instructions and caveats to start your journey of wonderment growing the Spiral Aloe. There are two articles attached to the website with more detailed information.
Landscape Horticulture Arborist
B.A Environmental Biology 1973 UCSB
Peace Corps Volunteer 1974-77 Lesotho
High School Science teacher
Botanical Researcher-Sehlabathebe National Park
MSc. General Agricultural Plant Sciences Cal Poly - San Luis Obispo
Thesis "The Seed Ecology of Aloe Polyphylla" 1979
Cactus and Succulent grower, propagator 1980-82
Retail Nursery Management 1982-83
Landscape Contractor 1982-present
International Society of Arboriculture
Certified Arborist #3644
Landscape contractor #690974
Cal-DPR Qualified Applicator #118707
Graduate ASCA Consulting Academy
The Age of Information Technology has changed every industry and profession in America. Software writers have delivered very workable solutions on new hardware which enable professionalism efficiency and timely flow of information in all industries. We have come to expect this from every business that competes in the marketplace. Landscape maintenance contractors in both commercial and private sectors have achieved some of this in their offices, but fall short of delivering on many aspects of horticulture their clients assume are part of the program. This is the meaning of the term 'horrorculture': a departure from plant health based maintenance which produces profit for the contractor but slowly diminishes plant health of clients landscape, shortening the life of a plant which should mature into 'traffic stopping' show.
Landscape horticulture is very complex and multidisciplinary. On the front lines of the biological economy of nature and the business economy of civilization this industry is plagued by real problems which derail the expectations and best laid plans of all. Many of these problems were started by architects or designers, who mean well but are never commissioned to write a management plan for their own work. One of my favorite UC Co-op agents (now retired) Dr. Pavel Svihra has described landscape maintenance as a "multilayered nightmare." This article attempts to explain the gulf between client expectations and contractor performance, and why the prevailing business model cannot achieve the clients' goals. A new business model is presented to bridge the gulf between the clients' rightful expectations of service and the contractors' obligation to deliver textbook quality maintenance and enhancement. Neither party to a contract signs a blank check, but the client frequently gets short changed because the contractors' business economics only permit so much service, and the client holds the "sword of Damocles" over the contractors head, forcing him to attempt impossible miracles without the budget to accomplish it. Such an arrangement is a LOSE-LOSE game which can be easily corrected by a new business model which creates a WIN-WIN deal for both parties and the landscape.
The use of plant growth regulators (PGR's) in horticulture is well established by growers of horticultural commodities, and much university research has explained the biochemical pathways which are the targets of the applied chemical. They all interfere with the synthesis of the Gibberellins, a primary growth hormone made in apical meristems.Thus deprived of the stimulus for growth the effects are a great reduction in new growth at the apical meristems of the plant. They are metabolized slowly, and have lasting effects. The plants' physiology changes when new growth ceases. There is more starch available for root tissues enhancement.