In order to properly prune a tree or to repair damage to the trunk requires a basic understanding of tree structure. A cross section of a tree trunk reveals it is composed of many layers (Figure 1). Each year a tree essentially grows a new “coat of wood” over the older wood. The outside layer of the tree is dead bark which provides protection from the environment. The inner bark layer is composed of live tissue that transports food downward. Between the bark and wood is the cambium layer which is responsible for increases in tree diameter (by creating annual rings) and responds to injury by producing callus tissue.

The annual rings of wood are composed of large pores that carry water up to the leaves. Each annual ring is essentially a vertical cylinder. The outer 4 to 20 annual rings (referred to as sapwood) are usually alive and light-colored. Wood in the center of a large tree (referred to as heartwood) is composed of dark-colored, dead cells used for storage. Ray cells cut across the annual rings; they distribute food to living cells. 

Branches

Branches are attached to the tree trunk by interlocking branch and trunk tissue. A new layer of interlocking tissue is produced each year over the previous layers. A woody branch collar, produced by the trunk, holds the branch base. When branches on the main trunk that have a narrow angle increase in diameter they eventually run out of room to grow. The branch bark becomes surrounded by woody trunk and branch tissue. The bark that becomes overgrown is referred to as included bark (Figure 2). The union is weak and likely to split.

During the 17th through 19th centuries, a woman expressing passionate love for another woman was fashionable, accepted, and encouraged.[90] These relationships were termed romantic friendships, Boston marriages, or “sentimental friends”, and were common in the U.S., Europe, and especially in England. Documentation of these relationships is possible by a large volume of letters written between women. Whether the relationship included any genital component was not a matter for public discourse, but women could form strong and exclusive bonds with each other and still be considered virtuous, innocent, and chaste; a similar relationship with a man would have destroyed a woman’s reputation. In fact, these relationships were promoted as alternatives to and practice for a woman’s marriage to a man.

One such relationship was between Lady Mary Wortley Montagu, who wrote to Anne Wortley in 1709: “Nobody was so entirely, so faithfully yours … I put in your lovers, for I don’t allow it possible for a man to be so sincere as I am.”[92] Similarly, English poet Anna Seward had a devoted friendship to Honora Sneyd, who was the subject of many of Seward’s sonnets and poems. When Sneyd married despite Seward’s protest, Seward’s poems became angry. However, Seward continued to write about Sneyd long after her death, extolling Sneyd’s beauty and their affection and friendship.[93] As a young woman, writer and philosopher Mary Wollstonecraft was attached to a woman named Fanny Blood. Writing to another woman by whom she had recently felt betrayed, Wollstonecraft declared, “The roses will bloom when there’s peace in the breast, and the prospect of living with my Fanny gladdens my heart:—You know not how I love her.”[94] Wollstonecraft’s first novel Mary: A Fiction, in part, addressed her relationship with Fanny Blood. Eleanor Butler and Sarah Ponsonby had a relationship that was hailed as devoted and virtuous, after eloping and living 51 years together in Wales.

Perhaps the most famous of these romantic friendships was between Eleanor Butler and Sarah Ponsonby, nicknamed the Ladies of Llangollen. Butler and Ponsonby eloped in 1778, to the relief of Ponsonby’s family (concerned about their reputation had she done similar with a man)[96] to live together in Wales for 51 years and be thought of as eccentrics.[97] Their story was considered “the epitome of virtuous romantic friendship” and inspired poetry by Anna Seward and Henry Wadsworth Longfellow.[98] Diarist Anne Lister, captivated by Butler and Ponsonby, recorded her affairs with women between 1817 and 1840. Some of it was written in code, detailing her sexual relationships with Marianna Belcombe and Maria Barlow.[99] Both Lister and Eleanor Butler were considered masculine by contemporary news reports, and though there were suspicions that these relationships were sapphist in nature, they were nonetheless praised in literature.[100][101]

Romantic friendships were also popular in the U.S. Enigmatic poet Emily Dickinson wrote over 300 letters and poems to Susan Gilbert, who later became her sister-in-law, and engaged in another romantic correspondence with Kate Scott Anthon. Anthon broke off their relationship the same month Dickinson entered self-imposed lifelong seclusion.[102] Nearby in Hartford, Connecticut, African American freeborn women Addie Brown and Rebecca Primus left evidence of their passion in letters: “No kisses is like youres”.[103] In Georgia, Alice Baldy wrote to Josie Varner in 1870, “Do you know that if you touch me, or speak to me there is not a nerve of fibre in my body that does not respond with a thrill of delight?”[104]

Around the turn of the 20th century the development of higher education provided opportunities for women. In all-female surroundings, a culture of romantic pursuit was fostered in women’s colleges. Older students mentored younger ones, called on them socially, took them to all-women dances, sent them flowers, cards, and poems that declared their undying love for each other.[105] These were called “smashes” or “spoons”, and they were written about quite frankly in stories for girls aspiring to attend college in publications such as Ladies Home Journal, a children’s magazine titled St. Nicholas, and a collection called Smith College Stories, without negative views.[106] Enduring loyalty, devotion, and love were major components to these stories, and sexual acts beyond kissing were consistently absent.[105] Women who had the option of a career instead of marriage labeled themselves New Women, and took their new opportunities very seriously.[note 7] Faderman calls this period “the last breath of innocence” before 1920 when characterizations of female affection were connected to sexuality, marking lesbians as a unique and often unflattering group.[105] Specifically, Faderman connects the growth of women’s independence and their beginning to reject strictly prescribed roles in the Victorian era to the scientific designation of lesbianism as a type of human sexual behavior.

The varied meanings lesbian has known since the early 20th century caused some historians to revisit historic relationships between women before the wide usage of the word was defined by erotic proclivities. Discussion from historians caused further questioning of what qualifies as a lesbian relationship. As lesbian-feminists asserted, a sexual component was unnecessary in declaring oneself a lesbian if her primary and closest relationships were with women. When considering past relationships within appropriate historic context, there were times when love and sex were separate and unrelated notions.[67] In addition to the difficulties of this qualification, female sexuality is often not adequately represented in texts and documents. Until very recently, much of what has been documented about women’s sexuality has been written by men, in the context of male understanding, and relevant to women’s associations to men—as their wives, daughters, or mothers, for example.[68] Often artistic representations of female sexuality suggest trends or ideas on broad scales, giving historians clues as to how widespread or accepted erotic relationships between women were.

Ancient Greece and Rome

History is often analyzed with contemporary ideologies; Ancient Greece as a subject enjoyed popularity by the ruling class in Britain during the 19th century. Based on their social priorities, early Greek scholars interpreted Greece as a westernized, white, and masculine society, and essentially removed women from historical importance.[69] Women in Greece were sequestered with each other, and men with men. In this homosocial environment erotic and sexual relationships between males was common, and were recorded in literature, art, and philosophy. Hardly anything is recorded about homosexual activity between women. There is some speculation that similar relationships existed between women and girls. The poet Alcman used the term aitis, as the feminine form of aites — which was the official term for the younger participant in a pederastic relationship.[70] Aristophanes, in Plato’s Symposium, mentions women who love women, but uses the term trepesthai (to be focused on) instead of eros, which was applied to other erotic relationships between men, and between men and women.[71]

Historian Nancy Rabinowitz argues that ancient Greek red vase images portraying women with their arms around another woman’s waist, or leaning on a woman’s shoulders can be construed as expressions of romantic desire.[72] Much of the daily lives of women in ancient Greece is unknown, specifically their expressions of sexuality. Although men participated in pederastic relationships outside of marriage, there is no clear evidence that women were allowed or encouraged to have same sex relationships before or during marriage as long as their marital obligations were met. Women who appear on Greek pottery are depicted with affection, and in instances where women appear only with other women, their images are eroticized: bathing, touching one another, with dildos, and sometimes with imagery also seen in depictions of heterosexual marriage or pederastic seduction. Whether this eroticism is for the viewer or an accurate representation of the scene is unknown.[73][70]

Women in Rome were similarly subject to men’s definitions of sexuality, what was considered to be well-mannered, and what was not. Though works of art in Rome depict female homoeroticism, it is unknown if the art was intended to reflect accurate representations of same sex love, or if it was created for the benefit of men who found lesbian sex appealing. Sappho was a subject that several Roman scribes used. Generally, however, Sappho’s virtues were associated in Roman literature with Muses, Aphrodite, and weddings.