Caprifig (male trees) generally produce 3 syconium crops per year: the summer "profichi" crop (with wasp-bearing "gall" flowers & pollen-bearing male flowers); an autumn "mammoni" crop (wasp-bearing & abortive male flowers); and an overwintering "mamme" crop (wasp-bearing & abortive male flowers). The mammoni crop is sometimes late or doesn't develop and is replaced by overwintering mamme crop.

If the 3 crops of caprifigs overlap each other in the proper sequence (i.e. are in sync.) the female fig wasps can move from the profichi to mammoni and to overwintering mamme crops; however, if any crop should fail, it would be fatal to the wasps living in the protective figs unless they had figs on other trees in which to breed. If there is a considerable time lapse between profichi, mammoni and mamme crops, then another caprification will be necessary, possibly from another caprifig or different caprifig variety. According to fig authority Dr. Gustav Eisen (1901b), different caprifig varieties have one, two or three crops of syconia: uniferi, biferi, & triferi. He recommends growing several different caprifig varieties in fig orchards.

As of 4 July 2020 I noticed a time lapse between profichi and receptive mammoni crops in my 'Vista Caprifig' in Twin Oaks Valley, northern San Diego County. The profichi crop was dried up and there were no female Blastophaga wasps inside the syconia. I assumed they all exited. The mammoni crop were just appearing as small, hard syconia that were not yet penetrated by female wasps. The mammoni crop appeared to be out of sync. with exiting wasps from profichi crop. According to Ali Sarkhosh, et al. (The Fig: Botany, Production & Uses, 2022), the receptive stage of mammoni coincides with the donor stage of profichi; however, the production of mammoni syconia may be irregular. In fact, the mammoni crop may not develop and wasps may lay their eggs in the receptive mamme crop one or 2 months later. Can female Blastophaga wasps survive outside their profichi syconia to lay their eggs in a delayed mammoni or mamme crop when they are receptive?

For a dioecious species like Ficus carica, it would be normal and advantageous for wasps exiting the profichi crop to pollinate female trees for seed production and perpetuation of the species in its natural habitat. Therefore, a time lapse between profichi and receptive mammoni crops may be beneficial to the species.

On 23 July 2020 I examined a developing mammoni syconium on my 'Vista Caprifig' and to my surprise discovered the presence of several dead female Blastophaga wasps in the ostiole region and in the interior. So even though the mammoni crop appeared to be late, this syconium was still penetrated by ovipositing wasps. Wasp larvae were also present in ovaries of short-style female flowers within mammoni syconia examined 26 Aug 2020. The following image of a mammoni syconium was taken 1 Sept 2020. It contains many wasp-bearing ovaries (psenocarps). So it looks like even though the initial mammoni crop appeared out of sync. with exiting wasps from profichi crop, at least some mammoni syconia received ovipositing wasps and developed a new generation of wasps for the fall mamme crop.

In early June 2022, when my 'Vista Caprifig' profichi crop was shedding pollen & releasing female Blastophaga wasps, receptive mammoni syconia were not visible (or very minute) on the new 2022 growth (see following image). I have not observed another mature, syconia-bearing caprifig in my immediate neighborhood; however, I do have nearby female trees ('Calimyrna' & 'Verte') that do get pollinated. This would explain the fig seedlings that appear in my yard. In 2020, the developing, receptive mammoni crop did not appear until later in June. I plan to document & photograph the 1st receptive mammoni to appear on this tree in 2022 (see below). My question is: Where do these newly released female wasps go during the interim before receptive mammoni syconia develop? Some obviously go to my nearby female trees ('Calimyrna' & 'Verte'). Are there late-maturing profichi that supply wasps to the receptive mammoni crop later in June?

According to Kjellberg et al. (1988), female fig wasps from mature profichi syconia may survive until receptive mammoni or mamme syconia are available. "Interestingly, on the island of Zia (Greece), the wasps were thought to spend some time on the local thistle, Scolymus hispanicus. Present-day inhabitants of the Kerkennah Islands in Tunisia never cultivate the land beneath male F. carica trees, possibly in the belief that fig wasps can subsist there on nectar-rich plants."

On 10 June 2022 I found one receptive syconium on the 2022 growth of my Twin Oaks Valley 'Vista Caprifig'. I am reasonably certain it was a mammoni syconium because the profichi crop on an older 2021 branch had already shed wasps and was wilted. In addition, the profichi crop was initiated the previous fall of 2021. Numerous wasps from the profichi crop covered the receptive mammoni. At this time most of the syconia in leaf axils were very small and not receptive. Whether all of these minute syconia will develop into mature mammonii by August is unknown at this time. I am not even certain they are mammoni or mamme.

Unfortunately, many of the wasps were carried away by Argentine ants (Linepthema humile) before they entered the ostiole to lay their eggs. To alleviate the Argentine ant attacks, I placed Terro®: ant bait under the tree. This is a borax + sugar solution (lethal to ants) that worker ants take back to their nests. Blastophaga wings protruding from the ostiole is clear evidence that one or more wasps have penetrated the syconium.

According to Ira Condit, "Caprifigs and Caprification" (1920), Ficus pseudocarica is different from F. carica because it produces pollen-bearing stamens in all three crops of syconia: profichi, mammoni & mamme. This is also true of the 'Vista Caprifig' including the overwintering mamme crop.

Several years ago I noticed a young caprifig in a neighbor's yard (about 200 feet away), presumably an offspring from my 'Vista Caprifig.' In January 2024, I examined its mamme crop and discovered it was more like typical caprifigs of Ficus carica, quite unlike F. pseudocarica described by Condit (1920). In fact, there were relatively few male flowers in mamme syconia compared with 'Vista Caprifig' and no pollen.

Note: When mammoni syconia have been pollinated by fig wasps from profichi crop, the drupelet may contain a seed if the wasp did not oviposit inside the ovary of drupelet. As stated above, drupelets are the individual fruits (ripened ovaries) within the syconium. They resemble miniature drupes surrounded by an ovary wall (pericarp) with a sclerified endocarp layer. The seed coat develops from the outer layer (integuments) of ovule within the ovary. In drupelets containing a seed, the seed coat and endocarp layers are close together. If seed-bearing endocarps sink in water they are probably viable. I have extracted up to 10 presumably viable endocarps from one syconium (see right panel of following image). For more details see I.J. Condit "The Structure and Development of Flowers in Ficus carica L." (Hilgardia, 1932).

Since figs are protogynous, with female flowers receptive before male flowers shed pollen, cross pollination between different plants is generally favored. This is especially true in dioecious (gynodioecious) figs, such as Ficus carica with male (caprifig) and female trees. Seed production in caprifig mammoni syconia results from self pollination (selfing) if both gametes came from same caprifig parent and are genetically identical. Protogyny is probably not a issue because the gametes come from different syconia at different times on caprifig branches (profichi & mammoni). This may be an example of "geitonogamy" [guy-ton-OG-uh-mee], self pollination between different flowers on the same plant with genetically identical gametes. Self pollination within the same flower is autogamy and the genetic result is the same as geitonogamy. Plants have evolved many adaptations to avoid the deleterious effects of inbreeding, known as inbreeding depression.

According to Hossaert-McKey & Bronstein (American Journal of Botany Vol. 88, 2001), selfing occurs in the tropical, monoecious fig Ficus aurea without negative effects of inbreeding. In fact, no negative effects of selfing could be demonstrated on syconium retention, number of vacant ovaries, seed set, or seed germination; however, wasp production had a tendency to be higher after self-pollination. Dioecy (populations with separate male & female individuals) favors cross pollination and is considered evolutionarily advanced in figs compared with ancestral monoecious species.

Lateral illustration of spherical cystolith in above leaf image. Calcareous lithocyst is suspended by central stalk within outer cell called a lithocyst.   More Images & Information About Ficus Cystoliths

Seed-bearing endocarps from 'Vista Caprifig' mammoni syconia were also collected & germinated in fall 2023. Compared with seed-bearing endocarps from cross pollinated female trees there was a low ratio of seedling survival from self-pollinated mammoni syconia. Walter Swingle (Science, 1899) also extracted a low ratio of viable seeds from caprifig mammoni syconia over a century ago.

Other researchers have also extracted viable seeds from caprifig mammoni syconia and successfully germinated them. According to G.P. Rixford (U.S. Department of Agriculture Bulletin No. 732, 1918), 75 fertile seeds were contained in a single mammoni syconium. On page 53 of The Fig (1947), Condit reported self-pollinated mammoni figs with profichi pollen from the same tree: "Of 89 seedlings grown from such seeds, 62 bore caprifigs and 27 bore edible figs." These and other self-pollination studies have shown that maleness is dominant in caprifigs.

According to Storey (Advances in Fruit Breeding, 1975), all commercial caprifigs probably originated from common edible fig seeds from homozygous female (ga/ga) trees and, therefore, are heterozygous (GA/ga). According to Condit (1920), cuttings of Smyrna figs and caprifigs were introduced into California in 1882. The fruit from these trees all dropped because of the lack of caprification. In 1890 caprifig cuttings with wasp-bearing syconia were also introduced. It is impossible to be certain if any of these caprifigs were homozygous. Naturalized female trees that have been pollinated develop syconia that are conspicuously pinkish-red inside, with numerous drupelets (endocarps) containing viable seeds.

Sex determination in the common fig (Ficus carica) may be controlled by two pairs of alleles located on one pair of homologous chromosomes. Data from breeding experiments support this hypothesis. [From Storey, W.B. 1975. Figs (pp. 568-589). In: Advances in Fruit Breeding, Purdue University Press, West Lafayette, Indiana.]. Functional males are heterogametic for sex determination was corrobarated by T.L. Parish, H.O. Koelewijn, and P.J. van Dijk in 2004 (Sexual Plant Reproduction 17: 17-22). They studied DNA fragments (Amplified Restriction Length Polymorphisms or AFLPs) in the gynodioecious species Ficus fulva. The alleles for short-style female flowers and production of male flowers (GA) are dominant over the recessive alleles (ga) for long-style female flowers and suppression of male flowers. Since seeds from the mammoni crop result from self pollination, the offspring of heterozgous caprifig (GA/ga) would have a 3:1 Mendelian ratio for caprifigs compared with female trees. Although a homozygous (GA/GA) caprifig is apparently rare, all the offspring from self pollination would carry the dominant caprifig gene (GA). Sex determination by genes & chromosomes is discussed in more detail in Section 15 on this page.

Careful observations indicate that my 'Vista Caprifig' pollinated a parthenocarpic 'Verte' fig at my home because the latter tree produces delicious green syconia with bright red interior that are loaded with seed-bearing endocarps. It is visited by numerous birds when prolific 2nd (main) crop is ripe. A recent seedling tree appeared on a bank near the 'Verte' tree. It produces female syconia resembling the 'Verte' loaded with seeds. I feel reasonably certain that it is a hybrid between my 'Vista Caprifig' and my 'Verte' fig. If the caprifig parent was homozygous GA/GA, all the offspring would be male caprifigs with dominant GA allele. Therefore, if 'Vista Caprifig' is the pollen parent, and if the 'Verte' fig is the seed parent, then I must conclude that my 'Vista Caprifig' is heterozygous (GA/ga). Self pollination of its mammoni crop could yield a 3:1 ratio of male & female seedlings; however, the relatively few viable seeds from this male fig, and the probability of a female seedling are quite low. In addition, the alleles for "persistence" and "caducous" can complicate ratios of offspring (see following paragraph).

Another very complicated, genetically determined characteristic is persistent vs. caducous figs. Persistent (P) is a dominant allele in which unpollinated & unfertilized syconia remain on the tree. Caducous (+) allele is recessive to persistent (P): Unpollinated syconia drop from the tree prematurely. Persistence is complicated by the fact that it also causes ovule abortion. According to W.B. Storey (1975), since this allele is egg lethal it can only be carried in the sperm. In other words, it cannot be passed on from a persistent female tree. The homozygous genotype PP is not possible. The recessive wild type allele (+) results in caducous syconia and normal ovule development. It can be carried by the egg and sperm. Therefore the only possible genotypes for caprifigs and female trees are P+ and ++. Persistent caprifigs and persistent female trees must be heterozygous (P+). Caducous caprifigs and caducous female trees must be homozygous ++. Mature pollinated syconia on heterozygous female trees having the allele for persistence (P) may contain hollow drupelets (cenocarps) as well as normal seed-bearing drupelets. This allele does not appear advantageous to the female fig, although if wasp-bearing caprifigs are nearby, the syconia are capable of producing seeds. I am only guessing that my 'Vista Caprifig' carries the dominant allele for persistent syconia.

The explanation for a dominant, persistent, egg lethal allele explains some genetic ratios in figs: "Lethality of the P allele to ovules receiving it enforces heterozygosity on all trees with persistent syconia and precludes the probability of homozygosity in seedling progenies regardless of whether the persistent phenotype serves as a seed parent or as a pollen parent. This accounts for the deviation from the 3:1 ratio which one ordinarily expects from the mating of monogenic genotypically identical heterozygotes. It accounts, also, for the failure of the persistent phenotype to appear when the flowers of a tree of the persistent phenotype are pollinated with pollen from a tree of the caducous phenotype." [The Fig by W.B. Storey, J.E. Enderud, W.F. Saleeb, and E.M. Nauer. 1977.] The previous cross is P+ Female with ++ Caprifig; however, female parent cannot contribute egg-lethal P allele, so all offspring would be caducous ++. Persistent female figs include many of the varieties of figs labeled "parthenocarpic."

During the summer of 2022 I carefully watched the developing syconia on my 'Vista Caprifig' following the exodus of wasps from the profichi crop. Several crops of wasp-bearing syconia developed on the branches after the profichi crop withered. Upon maturation these changed from green to purple. I assumed these were mammoni because they followed the profichi crop; however, there were several crops prior to the overwintering mamme crop in fall and the initiation of profichi buds that will develop on the next year's stem growth. The following image (taken 31 August) shows a mature purple syconium with exiting wasps entering 2 smaller green mammoni syconia. Most fig references state that syconia developing after the profichi crop and ripening before winter are called mammoni. On my caprifig these syconia were produced throughout the summer of 2022. None of these marked with colored string became overwintering, wasp-bearing mamme.

During summer 2022, I carefully observed the 'Vista Caprifig' at my home in Twin Oaks Valley, San Marcos. Mammoni syconia were produced throughout the summer months, not just in June when the mature profichi crop was releasing Blastophaga female wasps & pollen. In fact, some of the mammoni syconia contained wasp-bearing psenocarps, some contained hollow cenocarps, and some contained seed-bearing endocarps. In addition, some syconia contained pollen-bearing male flowers. The following image of 2 syconia was taken on a rainy day in October. The syconia were marked with red string in August. They ripened into purple, mature syconia that withered by November. They did not become overwintering mamme.

According to W.B. Storey (1975), there is a dominant mutant allele (P) for persistent syconia and ovule abortion. This allele is egg lethal so it can only be carried in the sperm. In other words, it cannot be passed on from a persistent female tree. The homozygous genotype PP is not possible. A recessive wild type allele (+) results in caducous syconia and normal ovule development. It can be carried by the egg and sperm. Therefore the only possible genotypes for caprifigs and female trees are P+ and ++. Persistent caprifigs and persistent female trees must be heterozygous (P+). Mature pollinated syconia on heterozygous female trees having the allele for persistence (P) may contain hollow drupelets (cenocarps) as well as normal seed-bearing drupelets. Although I don't have a specific reference, I don't see why the persistent allele (P) could not occur in wild populations of F. carica. This allele does not appear advantageous to the female fig, although if wasp-bearing caprifigs are nearby, the syconia are capable of producing seeds.

The explanation (hypothesis) for a dominant, persistent, egg lethal allele explains some genetic ratios in figs: "Lethality of the P allele to ovules receiving it enforces heterozygosity on all trees with persistent syconia and precludes the probability of homozygosity in seedling progenies regardless of whether the persistent phenotype serves as a seed parent or as a pollen parent. This accounts for the deviation from the 3:1 ratio which one ordinarily expects from the mating of monogenic genotypically identical heterozygotes. It accounts, also, for the failure of the persistent phenotype to appear when the flowers of a tree of the persistent phenotype are pollinated with pollen from a tree of the caducous phenotype." [The Fig by W.B. Storey, J.E. Enderud, W.F. Saleeb, and E.M. Nauer. 1977.]

This is a complicated subject when discussing the biology of Ficus carica. In general, unpollinated parthenocarpic cultivars with the persistent gene must be propagated by cuttings because the drupelets in their syconia are hollow cenocarps without seeds. These cultivars have been grown and selected for flavorful "figs" and, like many other excellent fruit cultivars, must be propagated asexually in order to obtain clones. Cultivars such as the 'Verte' are valuable because they are absolutely delicious and do not require wasp pollination in order to set fruit. If these parthenocarpic cultivars are pollinated by a nearby caprifig they can produce seed-bearing drupelets in addition to hollow drupelets (cenocarps). The remains of female F. carica syconia have been discovered in archaeological sites of the Jordon Valley that date back 11,400 years. They are clearly persistent, parthenocarpic syconia containing hollow drupelets (cenocarps). When M.E. Kislev concluded they were planted by cuttings and possibly represented the first known domesticated plants, perhaps he assumed that the trait for persistent syconia was unique to seedless fig cultivars. According to Storey (1975), this gene can occur in both female trees and caprifigs. It is passed to female progeny in the sperm of caprifig pollen parents. Female parthenocarpic trees with the persistent gene can produce seeds if they are pollinated by fig wasps. The ancient syconia of the Jordon Valley with hollow cenocarps could have come from unpollinated female trees that grew from seeds.