Ignatia: 'the world’s more full of weeping ...'
Ignatia is best known as a remedy for grief ‘where a person’s acute response … is to weep’. But given its status as a homeopathic polycrest its profile is far more rich and nuanced than this one application.
Bereavement and abandonment
In Ignatia, weeping following bereavement, abandonment or bad news ‘comes in bursts’  marked by sobbing, which can alternate with sighing and a suppression of the tears. Ignatia, particularly when adult, prefers to weep when alone  and the emotion often results in physical symptoms, notably a sensation like a ball rising in the throat (globus hystericus). Other distinctive traits include inappropriate laughter, fainting, hiccuping, twitching, a spasmodic cough, and being easily startled, which in Ignatia can be traced back to a specific emotional cause. This is a chilly remedy, generally better for warmth and worse for cold.
Underlying these keynote physical symptoms is an acutely sensitive mind. Ignatia is romantic, emotional, idealistic and artistic.[5, 2] Impressions from the outside world are acutely felt (tobacco smoke or other strong smells can be unbearable). Ignatia is irresolute with 'a heart-breaking jumble of contradictory impulses, immature in formation and destructive in action’.
Ignatia's mental distress can result in apparently hysterical behaviour, mood swings, jealousy, twitching, spasms and trembling, which may, especially in children, progress to convulsions. Unresolved grief can produce anxiety, depression or insomnia, which the patient can always trace back to a specific emotional upset. There may be back pain, irritable bowel syndrome, shooting pains in the rectum. Physical symptoms can arise (and disappear) without any traceable physiological reason, are often closely focused in a single spot, and often relieved by pressure or lying on the painful side. Ignatia headaches are also distinctive; with the sensation of a nail being driven into the side of the head.
The unpredictability, rapid mood swings and sometimes extreme behaviour give the appearance of hysteria, but it is the rapid changeability of Ignatia, rather than being actually out of control which produce this impression and can mean that Ignatia seems rude to other people. They can ‘come across as bossy or extremely touchy.’  Certainly Ignatia patients are worse for consolation and ‘there is nothing that you can say’ that will please them. The essence of this remedy is its passion. Its strong mental symptoms are provoked by external circumstances, their relation to the patient’s high expectations and the acute sense of diappointment which may be felt when these are not met.
The subject tends to be dark, spare, long-fingered and unfeminine in stature, with something of a moustache, a tense alert manner, and quick, gauche movements. The head may hang forward, and ready flushing leads to rapid changes of facial colour.
A stage on the journey
Overall, this is not a remedy for deep physical pathology, and usually not a constitutional remedy so much as one appropriate for a stage on a journey. Although this stage is one we must all travel, the Ignatia way of coping is essentially a feminine way. Historically this has meant that most prescriptions have been for women, but society is changing, and nowadays it makes more sense to think of male and female principles, which may be manifested by either sex. Keith Souter captures the romantic associations of Ignatia through the story of the willow pattern plate. Two separated lovers yearn for each other and cannot live apart. They run away together, and, when finally discovered by a jealous father who burns down their house, are helped by the gods who turn their spirits into two love birds, reuniting them for all eternity. Souter’s vignette firmly places both the lovers, female and male, as Ignatia constitutions.
Origins and correspondences
How Hahnemann himself came to prove this seed of Strychnos ignatia, the 'St Ignatius bean’, I do not know. It hails from the Philippines and is a climbing shrub of the Loganiaceae family with ovate glabrous leaves and white tubular flowers which transform into berries containing about twenty bitter seeds, the source of the mother tincture. These contain significant amounts of the poison strychnine. The beans were brought to Europe by the Jesuits in the seventeenth century, and named after the founder of their order Ignatius Loyola; they were used to treat gout, epilepsy, asthma and cholera. Hahnemann compared Ignatia and Nux com at his initial proving. These remedies share an intense sensory impressionability, but whereas in Nux this produces anger, irascibility and over-excitability, in Ignatia the reaction is weeping and melancholy. 
Other significant correspondences of Ignatia include Pulsatilla, who shares Ignatia's tendency to weep, but in contrast seeks sympathy and consolation. Since Ignatia is associated with a stage on a longer journey, it is more appropriate for immediate or new bereavement or abandonment. Where the grief has become very deep-seated Nat mur is the remedy, and can often follow Ignatia. [5, 7]
"Strychnos ignatii - Köhler–s Medizinal-Pflanzen-132" by Franz Eugen Köhler - Köhler's Medizinal-Pflanzen in naturgetreuen Abbildungen mit kurz erläuterndem Texte : Atlas zur Pharmacopoea germanica, from MBG Rare Books. Licensed under Public Domain via Wikimedia Commons.
Here's a brief animation of the Willow Pattern Plate story
And the quotation in my heading? It’s from W. B. Yeates’ ‘The Stolen Child’ (1889).