#black triangle

There was no State persecution of lesbians in Nazi Germany. German homosexuals were deported on the basis of the §175 of the penal code, which referred exclusively to homosexual males. Some Nazi politicians argued in favour of expanding this article to include lesbians too, but this never happened because the general opinion was that lesbians, as women, could not genuinely be exclusively same sex attracted and could be 'reeducated' by the sexist laws that confined women to the family household. So lesbians weren't sent to any camp on the mere basis of their sexuality. Instead, Nazi lesbophobia looked like that:

closing down lesbian social places, like bars

shutting down lesbian newspapers and cultural magazines

(Weimar Germany had the most vibrant lesbian scene in Europe in the 1920s)

prohibition of lesbian subculture in general

increased social control of lesbians in the public sphere, with lesbians being reported to the authority if engaging in homosexual behaviour, which could lead to jail time (not camp)

In Austria, there were law articles explicitly condemning lesbianism, but lesbians were sent to Austrian jails, not to Nazi camps There is no archival evidence of one single lesbian being sent to a concentration camp (needless to say, there's even less evidence of a lesbian being sent to an extermination camp) for the sole reason of her sexuality. In Ravensbrück, the largest Nazi women-only concentration camp, we found record of only three women whose individual files mentionned their being lesbians. In two of those cases, those women had been deported because they were political opponents, with 'lesbian' an aggraviating factor. In the other case, the woman was deported as an 'asocial' and therefore made to wear the black triangle signifying 'asocial'

Then, in the late 80s, with the emergence of commemoration politics regarding the Nazi persecution of gay men, lesbian activists started attending commemorative events and that is when the argument that lesbians were made to wear the black triangle started to be told in speeches. Those speeches didn't quote any archival evidence. Personally, I think people got this idea because the memoirs and autobiographies that were published in the postwar era were, for the vast majority, written by former political deportees. In Nazi camps, political prisoners and asocial prisoners had a feud and fought to get to the top of the camp hierarchy. Both sides disparaged the others with lies. In Nazi camps, homosexual relationships were common among all prisoner categories, but political female prisoners weaponized this against asocial prisoners to paint them as 'masculine, dominating, Nazi-loving dykes', and they described them as such in their memoirs

tl;dr: lesbians weren't sent to camps en masse because of their sexuality, lesbians weren't made to wear the black triangle on the sole basis of their sexuality except for one lone recorded case, and the association of lesbians with the black triangle comes from postwar homophobic literature

I gotta say tho, Nazis burnt a lot of archival evidence so maybe there used to be a lot of texts pertaining to groups of lesbians being deported for their sexuality but since that has never been brought up in any witness testimony, that's unlikely

Also, badge identification systems varied from one camp to another (like in some camps, Jews didn't wear a yellow star but a blue and white armband), that's something people seem to forget when they want to argue one badge necessarily meant one thing exclusively. as for Sinti and Roma, the black triangle, the black triangle with a white Z in it, and the brown triangle were used depending on context. At Auschwitz, the people made to wear the black triangles were 'asocials' (people whose behaviour was detrimental for the well-being and development of the race; you could conceptualize it as a form of 'social racism' or racism applied to social classes as the poor were the most impacted by it; petty criminals, prostitutes, alcoholics, homeless people, etc.; they served a time in the camp before being allowed to come back to civil society. this was not the case for the Sinti and Roma who were associated with the 'asocial' because criminality, prostitution, etc, were deemed natural to the Romani race, and who weren't allowed to ever leave the camp because they were destined to be killed)

Books:

on the tensions between asocial and political prisoners

Nikolaus Wachsmann, KL: A History of the Nazi Concentration Camps

on the persecution of lesbians in Nazi Germany and Austria

Regis Schlagdenhauffen, Queer in Europe during the Second World War [yes, I know, it says 'queer', but it's a bad translation. the original title says 'homosexuals']

on political female prisoners associating lesbianism with asocial prisoners to paint them as masculine, dominating and pro-Nazi in their memoirs