diff --git a/src/components/phylogeny/PhylogenyView.vue b/src/components/phylogeny/PhylogenyView.vue
index 0e121543..53f70059 100644
--- a/src/components/phylogeny/PhylogenyView.vue
+++ b/src/components/phylogeny/PhylogenyView.vue
@@ -101,13 +101,13 @@
 
       <div class="card-footer">
         <div
-            class="btn-group"
-            role="group"
-            area-label="Phylogeny management"
+          class="btn-group"
+          role="group"
+          area-label="Phylogeny management"
         >
           <button
-              class="btn btn-danger"
-              @click="deleteThisPhylogeny()"
+            class="btn btn-danger"
+            @click="deleteThisPhylogeny()"
           >
             Delete phylogeny
           </button>
@@ -144,6 +144,66 @@
         />
       </div>
     </div>
+
+    <!-- Display taxonomic units in this phylogeny -->
+    <div class="card mt-2">
+      <h5 class="card-header">
+        Taxonomic units in this phylogeny
+      </h5>
+      <div class="card-body">
+        To add additional taxonomic units to this list, please label the corresponding node on the phylogeny.
+      </div>
+
+      <!--
+      <b-table-simple striped hover>
+        <b-thead>
+          <b-tr>
+            <b-th>Node label</b-th>
+            <b-th>Node type</b-th>
+
+          </b-tr>
+        </b-thead>
+      </b-table-simple>
+      -->
+
+      <b-table
+        striped
+        hover
+        :items="taxonomicUnitsTable"
+        :fields="['node_label', 'node_type', 'additional_taxonomic_units']"
+        :primary-key="node_label"
+        show-empty
+      >
+        <template #empty="scope">
+          <h4>No labels found in this phylogeny.</h4>
+        </template>
+        <template #emptyfiltered="scope">
+          <h4>No labels found after filtering.</h4>
+        </template>
+
+        <template #cell(additional_taxonomic_units)="row">
+          {{row.item.additional_taxonomic_units}} taxonomic units <b-button variant="primary" @click="addTUnitForNodeLabel(row.item.node_label)" class="float-right" size="sm">Add</b-button>
+        </template>
+
+        <template #row-details="row">
+          <b-card>
+            <b-row
+              v-for="(tunit, index) in getExplicitTUnitsForLabel(row.item.node_label)"
+              :key="row.item.node_label"
+              class="mb-12"
+            >
+              <Specifier
+                :key="'tunit_' + row.item.node_label + '_' + index"
+                :phylogeny="selectedPhylogeny"
+                :node-label="row.item.node_label"
+                :remote-specifier="tunit"
+                :remote-specifier-id="'tunit_' + row.item.node_label + '_' + index"
+              />
+            </b-row>
+          </b-card>
+        </template>
+      </b-table>
+    </div>
   </div>
 </template>
 
@@ -156,30 +216,21 @@ import { has } from 'lodash';
 import { mapState } from 'vuex';
 import { parse as parseNewick } from 'newick-js';
 
+import {PhylogenyWrapper, TaxonomicUnitWrapper} from '@phyloref/phyx';
 import ModifiedCard from '../cards/ModifiedCard.vue';
 import Phylotree from './Phylotree.vue';
 import Citation from '../citations/Citation.vue';
+import Specifier from "@/components/specifiers/Specifier.vue";
 
 export default {
   name: 'PhylogenyView',
-  components: { ModifiedCard, Phylotree, Citation },
+  components: {Specifier, ModifiedCard, Phylotree, Citation },
   data() {
     return {
       // Errors in the phylogenyId field.
       phylogenyIdError: undefined,
     };
   },
-  methods: {
-    deleteThisPhylogeny() {
-      // Delete this phylogeny, and unset the selected phylogeny so we return to the summary page.
-      if(confirm('Are you sure you wish to delete this phylogeny? This cannot be undone!')) {
-        this.$store.commit('deletePhylogeny', {
-          phylogeny: this.selectedPhylogeny,
-        });
-        this.$store.commit('changeDisplay', {});
-      }
-    },
-  },
   computed: {
     /*
      * The following properties allow you to get or set the phylogeny label,
@@ -246,11 +297,11 @@ export default {
 
       if (parenLevels !== 0) {
         errors.push({
-          title: 'Unbalanced parentheses in Newick string',
-          message: (parenLevels > 0
-            ? `You have ${parenLevels} too many open parentheses`
-            : `You have ${-parenLevels} too few open parentheses`
-          ),
+          title: "Unbalanced parentheses in Newick string",
+          message:
+            parenLevels > 0
+              ? `You have ${parenLevels} too many open parentheses`
+            : `You have ${-parenLevels} too few open parentheses`,
         });
       }
 
@@ -266,11 +317,74 @@ export default {
 
       return errors;
     },
+    terminalLabelsSorted() {
+      // Return a list of terminal (i.e. leaf node) labels sorted alphabetically.
+      return new PhylogenyWrapper(this.selectedPhylogeny).getNodeLabels('terminal').sort();
+    },
+    internalLabelsSorted() {
+      // Return a list of internal (i.e. non-leaf node) labels sorted alphabetically.
+      return new PhylogenyWrapper(this.selectedPhylogeny).getNodeLabels('internal').sort();
+    },
+    taxonomicUnitsTable() {
+      // Create a table of taxonomic units and their additional taxonomic units found in this phylogeny.
+      const terminalLabels = this.terminalLabelsSorted;
+      const internalLabels = this.internalLabelsSorted;
+
+      return terminalLabels
+        .map((nodeLabel) => ({
+          node_label: nodeLabel,
+          node_type: "Terminal node",
+          additional_taxonomic_units:
+            this.getExplicitTUnitsForLabel(nodeLabel).length,
+          _showDetails: this.getExplicitTUnitsForLabel(nodeLabel).length > 0,
+        }))
+        .concat(
+          internalLabels.map((nodeLabel) => ({
+            node_label: nodeLabel,
+            node_type: "Internal node",
+            additional_taxonomic_units:
+              this.getExplicitTUnitsForLabel(nodeLabel).length,
+            _showDetails: this.getExplicitTUnitsForLabel(nodeLabel).length > 0,
+          }))
+        );
+    },
     ...mapState({
       currentPhyx: state => state.phyx.currentPhyx,
       loadedPhyx: state => state.phyx.loadedPhyx,
       selectedPhylogeny: state => state.ui.display.phylogeny,
     }),
   },
+  methods: {
+    deleteThisPhylogeny() {
+      // Delete this phylogeny, and unset the selected phylogeny so we return to the summary page.
+      if (confirm('Are you sure you wish to delete this phylogeny? This cannot be undone!')) {
+        this.$store.commit('deletePhylogeny', {
+          phylogeny: this.selectedPhylogeny,
+        });
+        this.$store.commit('changeDisplay', {});
+      }
+    },
+    getExplicitTUnitsForLabel(nodeLabel) {
+      // Return the list of "explicit" taxonomic units for a phylogeny node, which is the list of
+      // taxonomic units listed in the additionalNodeProperties.
+      //
+      // This will not include "implicit" taxonomic units, which we generate from the node label.
+      return this.$store.getters.getExplicitTaxonomicUnitsForPhylogenyNode(
+        this.selectedPhylogeny,
+        nodeLabel
+      );
+    },
+    addTUnitForNodeLabel(nodeLabel) {
+      // Add a taxonomic unit to a node label.
+      this.$store.commit('addTaxonomicUnitToPhylogenyNode', {
+        phylogeny: this.selectedPhylogeny,
+        nodeLabel,
+        tunit: TaxonomicUnitWrapper.fromLabel(
+          "",
+          this.$store.getters.getDefaultNomenCodeURI
+        ),
+      });
+    },
+  },
 };
 </script>
diff --git a/src/components/specifiers/Specifier.vue b/src/components/specifiers/Specifier.vue
index 15215e24..275daf07 100644
--- a/src/components/specifiers/Specifier.vue
+++ b/src/components/specifiers/Specifier.vue
@@ -97,8 +97,8 @@
           Specifier details
         </h5>
 
-        <!-- Specifier type: internal or external -->
-        <div class="form-group row">
+        <!-- Specifier type: internal or external. Only applies to phylorefs! -->
+        <div v-if="phyloref" class="form-group row">
           <label
             class="col-form-label col-md-2"
             for="specifier-type"
@@ -424,9 +424,26 @@ export default {
       required: false,
       default: () => uniqueId('remoteSpecifierId'),
     },
-    phyloref: { /* The phyloreference containing this specifier */
+    /*
+     * There are two ways of visualizing a specifier:
+     * - The specifier may be a part of a phyloref, or
+     * - The specifier (really a taxonomic unit) may be a part of a phylogeny via the `representsTaxonomicUnits`
+     *   property of the `additionalNodeProperties` dictionary. This is specified in two ways: a phylogeny as
+     *   well as a nodeLabel.
+     */
+    /* The phyloreference containing this specifier */
+    phyloref: {
       type: Object,
-      required: true,
+      required: false,
+    },
+    /* The phylogeny and nodeLabel containing this specifier (really a taxonomic unit). */
+    phylogeny: {
+      type: Object,
+      required: false,
+    },
+    nodeLabel: {
+      type: String,
+      required: false,
     },
   },
   data() {
@@ -489,9 +506,12 @@ export default {
     },
     specifierType: {
       get() {
+        if (!this.phyloref) return undefined;
         return new PhylorefWrapper(this.phyloref).getSpecifierType(this.remoteSpecifier);
       },
       set(type) {
+        if (!this.phyloref) return undefined;
+
         this.$store.commit(
           'setSpecifierType',
           {
@@ -573,6 +593,12 @@ export default {
     phyloref() {
       this.recalculateEntered();
     },
+    phylogeny() {
+      this.recalculateEntered();
+    },
+    nodeLabel() {
+      this.recalculateEntered();
+    },
     remoteSpecifier() {
       this.recalculateEntered();
     },
@@ -645,24 +671,56 @@ export default {
       // Update remoteSpecifier to what we've got currently entered.
       const confirmed = confirm('Are you sure you want to delete this specifier?');
       if (confirmed) {
-        console.log('Deleting specifier: ', this.phyloref, this.remoteSpecifier);
-        this.$store.commit('deleteSpecifier', {
-          phyloref: this.phyloref,
-          specifier: this.remoteSpecifier,
-        });
+        if (this.phyloref) {
+          console.log("Deleting specifier from phyloref: ", this.phyloref, this.remoteSpecifier);
+          this.$store.commit('deleteSpecifier', {
+            phyloref: this.phyloref,
+            specifier: this.remoteSpecifier,
+          });
+        } else if (this.phylogeny && this.nodeLabel) {
+          console.log("Deleting taxonomic unit from phylogeny: ", this.phylogeny, this.nodeLabel, this.remoteSpecifier);
+          this.$store.commit('replaceTUnitForPhylogenyNode', {
+            phylogeny: this.phylogeny,
+            nodeLabel: this.nodeLabel,
+            tunit: this.remoteSpecifier,
+            delete: true,
+          });
+        }
       }
     },
     updateSpecifier() {
       const result = this.specifier;
 
       // If our local specifier differs from the remoteSpecifier, update it.
-      if (isEqual(result, this.remoteSpecifier)) return;
+      if (this.$store.getters.areTUnitsIdentical(result, this.remoteSpecifier))
+        return;
 
-      console.log('Updating specifier as ', result, ' differs from ', this.remoteSpecifier);
-      this.$store.commit('setSpecifierProps', {
-        specifier: this.remoteSpecifier,
-        props: result,
-      });
+      if (this.phyloref) {
+        console.log('Updating specifier in ', this.phyloref, ' as ', result, ' differs from ', this.remoteSpecifier);
+        this.$store.commit('setSpecifierProps', {
+          specifier: this.remoteSpecifier,
+          props: result,
+        });
+      } else if (this.phylogeny && this.nodeLabel) {
+        console.log(
+          "Updating tunit in ",
+          this.phylogeny,
+          " with node label ",
+          this.nodeLabel,
+          " as ",
+          result,
+          " differs from ",
+          this.remoteSpecifier
+        );
+        this.$store.commit('replaceTUnitForPhylogenyNode', {
+          phylogeny: this.phylogeny,
+          nodeLabel: this.nodeLabel,
+          tunit: this.remoteSpecifier,
+          tunit_new: result,
+        });
+      } else {
+        console.error("Specifier has neither phyloref nor phylogeny/nodeLabel combination: ", this);
+      }
     },
   },
 };
diff --git a/src/store/modules/phylogeny.js b/src/store/modules/phylogeny.js
index cc007d28..d7b262f7 100644
--- a/src/store/modules/phylogeny.js
+++ b/src/store/modules/phylogeny.js
@@ -3,25 +3,190 @@
  */
 
 import Vue from 'vue';
-import { has, keys, cloneDeep } from 'lodash';
+import { has, findIndex, isEqual, keys, cloneDeep } from 'lodash';
+import {PhylogenyWrapper, TaxonomicUnitWrapper} from "@phyloref/phyx";
+
+function areTUnitsIdentical(tunit1, tunit2) {
+  // A helper function for comparing two taxonomic units.
+  return isEqual(tunit1, tunit2);
+}
 
 export default {
+  getters: {
+    getExplicitTaxonomicUnitsForPhylogenyNode: () => (phylogeny, nodeLabel) => {
+      // Return any "explicit" taxonomic units for a phylogeny node, i.e. those with representsTaxonomicUnits
+      // in the additionalNodeProperties for this node label. This is as compared to implicit taxonomic units,
+      // which we generate from the node label.
+      if (
+        has(phylogeny, "additionalNodeProperties") &&
+        has(phylogeny.additionalNodeProperties, nodeLabel) &&
+        has(
+          phylogeny.additionalNodeProperties[nodeLabel],
+          "representsTaxonomicUnits"
+        )
+      ) {
+        return phylogeny.additionalNodeProperties[nodeLabel]
+          .representsTaxonomicUnits;
+      }
+      return [];
+    },
+    areTUnitsIdentical: () => (tunit1, tunit2) => {
+      // Test whether two taxonomic units are identical. This is intended to be the only place in Klados where
+      // we do this comparison. Eventually I will update this to normalize the TUs before comparison, which should
+      // help with https://github.com/phyloref/klados/issues/263
+      return areTUnitsIdentical(tunit1, tunit2);
+    },
+  },
   mutations: {
+    /**
+     * Insert a new taxonomic unit to a phylogeny node. If one is not provided, we insert an empty taxonomic unit
+     * without a nomenclatural code.
+     */
+    addTaxonomicUnitToPhylogenyNode(state, payload) {
+      if (!has(payload, "phylogeny")) {
+        throw new Error(
+          'addTaxonomicUnitToPhylogenyNode needs a phylogeny to modify using the "phylogeny" argument'
+        );
+      }
+      if (!has(payload, "nodeLabel")) {
+        throw new Error(
+          'addTaxonomicUnitToPhylogenyNode needs a node label to modify using the "nodeLabel" argument'
+        );
+      }
+
+      let tunitToBeAdded = TaxonomicUnitWrapper.fromLabel("");
+      if (has(payload, "tunit")) {
+        tunitToBeAdded = payload.tunit;
+      }
+
+      // If there is no additionalNodeProperties or representsTaxonomicUnits, set them up now.
+      if (!has(payload.phylogeny, "additionalNodeProperties"))
+        Vue.set(payload.phylogeny, "additionalNodeProperties", {});
+
+      if (!has(payload.phylogeny.additionalNodeProperties, payload.nodeLabel))
+        Vue.set(
+          payload.phylogeny.additionalNodeProperties,
+          payload.nodeLabel,
+          {}
+        );
+
+      if (!has(payload.phylogeny.additionalNodeProperties[payload.nodeLabel], "representsTaxonomicUnits"))
+        Vue.set(
+          payload.phylogeny.additionalNodeProperties[payload.nodeLabel],
+          "representsTaxonomicUnits",
+          []
+        );
+
+      // Now we can append the new taxonomic unit to it.
+      payload.phylogeny.additionalNodeProperties[payload.nodeLabel].representsTaxonomicUnits.push(tunitToBeAdded);
+    },
+    /**
+     * Replace or delete a taxonomic unit from a phylogeny node.
+     */
+    replaceTUnitForPhylogenyNode(state, payload) {
+      if (!has(payload, "phylogeny")) {
+        throw new Error(
+          'replaceTUnitForPhylogenyNode needs a phylogeny to modify using the "phylogeny" argument'
+        );
+      }
+      if (!has(payload, "nodeLabel")) {
+        throw new Error(
+          'replaceTUnitForPhylogenyNode needs a node label to modify using the "nodeLabel" argument'
+        );
+      }
+      if (!has(payload, "tunit")) {
+        throw new Error(
+          'replaceTUnitForPhylogenyNode needs a tunit to delete using the "tunit" argument'
+        );
+      }
+      if (!has(payload, "tunit_new") && !has(payload, "delete")) {
+        throw new Error(
+          "replaceTUnitForPhylogenyNode needs either a `tunit_new` to replace the tunit or `delete` to indicate it should be deleted."
+        );
+      }
+
+      console.log(
+        "Tried to replace or delete tunit: ", payload.tunit, " from phylogeny ", payload.phylogeny, " at node label ", payload.nodeLabel
+      );
+      if (!has(payload.phylogeny, "additionalNodeProperties")) {
+        console.error(
+          "Could not replace or delete: no additionalNodeProperties present in phylogeny."
+        );
+        return;
+      }
+
+      if (!has(payload.phylogeny.additionalNodeProperties, payload.nodeLabel)) {
+        console.error(
+          "Could not replace or delete: node label ",
+          payload.nodeLabel,
+          " not present in phylogeny."
+        );
+        return;
+      }
+
+      if (
+        !has(
+          payload.phylogeny.additionalNodeProperties[payload.nodeLabel],
+          "representsTaxonomicUnits"
+        )
+      ) {
+        console.error(
+          "Could not replace or delete: node label ",
+          payload.nodeLabel,
+          " does not have a representsTaxonomicUnits."
+        );
+        return;
+      }
+
+      const tunits =
+        payload.phylogeny.additionalNodeProperties[payload.nodeLabel]
+          .representsTaxonomicUnits;
+      const index = findIndex(tunits, (tu) =>
+        areTUnitsIdentical(payload.tunit, tu)
+      );
+
+      if (index < 0) {
+        console.error(
+          "Could not replace or delete: tunit ",
+          payload.tunit,
+          " as it is not present in tunits: ",
+          tunits
+        );
+        return;
+      }
+
+      // Delete or replace?
+      if (has(payload, "delete")) {
+        tunits.splice(index, 1);
+      } else if (has(payload, "tunit_new")) {
+        tunits.splice(index, 1, payload.tunit_new);
+      } else {
+        console.error(
+          "Neither `delete` nor `tunit_new` was set in payload, which should have been checked earlier: ",
+          payload
+        );
+      }
+    },
+    /**
+     * Set phylogeny properties.
+     */
     setPhylogenyProps(state, payload) {
-      if (!has(payload, 'phylogeny')) {
-        throw new Error('setPhylogenyProps needs a phylogeny to modify using the "phylogeny" argument');
+      if (!has(payload, "phylogeny")) {
+        throw new Error(
+          'setPhylogenyProps needs a phylogeny to modify using the "phylogeny" argument'
+        );
       }
-      if (has(payload, 'label')) {
-        Vue.set(payload.phylogeny, 'label', payload.label);
+      if (has(payload, "label")) {
+        Vue.set(payload.phylogeny, "label", payload.label);
       }
-      if (has(payload, 'curatorNotes')) {
-        Vue.set(payload.phylogeny, 'curatorNotes', payload.curatorNotes);
+      if (has(payload, "curatorNotes")) {
+        Vue.set(payload.phylogeny, "curatorNotes", payload.curatorNotes);
       }
-      if (has(payload, 'newick')) {
-        Vue.set(payload.phylogeny, 'newick', payload.newick);
+      if (has(payload, "newick")) {
+        Vue.set(payload.phylogeny, "newick", payload.newick);
       }
-      if (has(payload, '@id')) {
-        Vue.set(payload.phylogeny, '@id', payload['@id']);
+      if (has(payload, "@id")) {
+        Vue.set(payload.phylogeny, "@id", payload["@id"]);
       }
     },
   },