diff --git a/modules/services/taginfo.js b/modules/services/taginfo.js
index 72d7f0de4..5bb74b47e 100644
--- a/modules/services/taginfo.js
+++ b/modules/services/taginfo.js
@@ -191,7 +191,13 @@ export function init() {
                 page: 1
             }, parameters)), debounce, function(err, d) {
                 if (err) return callback(err);
-                var f = filterValues(parameters.key === 'cycle_network' || parameters.key === 'network');
+                // In most cases we prefer taginfo value results with lowercase letters.
+                // A few OSM keys expect values to contain uppercase values (see #3377).
+                // This is not an exhaustive list (e.g. `name` also has uppercase values)
+                // but these are the fields where taginfo value lookup is most useful.
+                var re = /network|taxon|genus|species/;
+                var allowUpperCase = (parameters.key.match(re) !== null);
+                var f = filterValues(allowUpperCase);
                 callback(null, d.data.filter(f).map(valKeyDescription));
             });
     };
diff --git a/test/spec/services/taginfo.js b/test/spec/services/taginfo.js
index 82d3f0765..3f791e9c3 100644
--- a/test/spec/services/taginfo.js
+++ b/test/spec/services/taginfo.js
@@ -195,6 +195,42 @@ describe('iD.serviceTaginfo', function() {
                 {'value':'US:MD','title':'State highways in the U.S. state of Maryland.'}
             ]);
         });
+
+        it('includes biological genus values with capital letters', function() {
+            var callback = sinon.spy();
+            taginfo.values({key: 'genus', query: 'qu'}, callback);
+
+            server.respondWith('GET', new RegExp('https://taginfo.openstreetmap.org/api/4/key/values'),
+                [200, { 'Content-Type': 'application/json' },
+                    '{"data":[{"value":"Quercus","description":"Oak", "fraction":0.5}]}']);
+            server.respond();
+
+            expect(callback).to.have.been.calledWith(null, [{'value':'Quercus','title':'Oak'}]);
+        });
+
+        it('includes biological taxon values with capital letters', function() {
+            var callback = sinon.spy();
+            taginfo.values({key: 'taxon', query: 'qu'}, callback);
+
+            server.respondWith('GET', new RegExp('https://taginfo.openstreetmap.org/api/4/key/values'),
+                [200, { 'Content-Type': 'application/json' },
+                    '{"data":[{"value":"Quercus robur","description":"Oak", "fraction":0.5}]}']);
+            server.respond();
+
+            expect(callback).to.have.been.calledWith(null, [{'value':'Quercus robur','title':'Oak'}]);
+        });
+
+        it('includes biological species values with capital letters', function() {
+            var callback = sinon.spy();
+            taginfo.values({key: 'species', query: 'qu'}, callback);
+
+            server.respondWith('GET', new RegExp('https://taginfo.openstreetmap.org/api/4/key/values'),
+                [200, { 'Content-Type': 'application/json' },
+                    '{"data":[{"value":"Quercus robur","description":"Oak", "fraction":0.5}]}']);
+            server.respond();
+
+            expect(callback).to.have.been.calledWith(null, [{'value':'Quercus robur','title':'Oak'}]);
+        });
     });
 
     describe('#roles', function() {