Moraceae, Gaudich., 1835

Bui, Van Huong, Vu, Dinh Duy, Pham, Mai Huong, Do, Van Hai, Doan, Hoang Son, Bui, Van Thanh, Dam, Ngoc Anh Luu, Truong, Ba Vuong & Gardner, Elliot M., 2022, HULLETTIA King ex Hook. f. (Moraceae), A newly recorded genus to the Flora of Vietnam, with its lectotypification and a revised key to Vietnamese Moraceae, Phytotaxa 550 (3), pp. 272-278 : 276-277

Key to the genera of Moraceae in Vietnam

This key presented applies to the native and naturalized general of Vietnam and follows recent taxonomic revisions in Moraceae . Previously-accepted genera are given in brackets. For genera represented only by one species, the species name is given in parentheses.

1a. Plants woody ...................................................................................................................................................................................... 2

1b. Plants not woody ................................................................................................................................................................................ 3

2a. Plants herbaceous or subshrubs, without latex; inflorescences cymose or spicate; stamens 4 ............................. Fatoua ( F. villosa )

2b. Plants herbaceous or succulent, within latex; inflorescences discoid to turbinate; stamens 2 or 3 (introduced)................................. .................................................................................................................................................................. Dorstenia ( D. contrajerva )

3a. Inflorescences urceolate (figs) stigmas and anthers not exposed at anthesis ; leaves usually trinerved at the base; lamina with waxy glandular spots at the base of the midrib or in the axils of the basal lateral veins beneath........................................................ Ficus

3b. Inflorescences not urceolate, stigmas and anthers exposed at anthesis ; leaves seldom trinerved at the base; lamina usually without waxy glandular spots .......................................................................................................................................................................... 4

4a. Staminate inflorescence capitate with at least a rudimentary involucre; stipules lateral ................................................................... 5

4b. Inflorescences not involucrate; stipules lateral or fully amplexicaul ................................................................................................. 6

5a. Leaves distichous, involucral bracts imbrivate, pistillate flowers one per inflorescence, stamens straight or inflexed in bud ........... ............................................................................................................................................................................................................ 7

5b. Leaves spirally arranged; involucral bracts not imbricate; pistillate inflorescences multiflorous, with flowers embedded in the receptacle; stamens straight in bud................................................................................................................... Hullettia ( H. dumosa )

6a. Inflorescences bisexual; staminate flowers numerous, surrounding 1-2 central pistillate flowers; (introduced) Brosimum ( B. utile )

6b. Inflorescences unisexual..................................................................................................................................................................... 8

7a. Inflorescences always unisexual, pistillate inflorescences involucrate; staminate inflorescences discoid with a well-developed involucre; stamens straight in bud; with self-pruning branches....................................................................... Antiaris ( A. toxicaria )

7b. Inflorescences sometimes bisexual, pistillate inflorescences not involucrate; staminate inflorescences capitate with a rudimentary involucre; stamens inflexed in bud; without self-pruning branches................................................ Streblus [ Streblus sect. Streblus ]

8a. Stamens one per flower, straight in bud; pistillate flowers at least partially connate ....................................................... Artocarpus

8b. Stamens 4‒5 per flower, inflexed in bud; pistillate flowers free, or if connate, the plants armed with spines ................................. 9

9a. Plants armed with curved or straight spines; staminate and pistillate inflorescences globose-capitate and multiflorous; tepals and bracts mostly with yellow dye accumulated in immersed glands ........................................................................................ Maclura

9b. Plants unarmed, or if armed, then with straights spines; staminate inflorescences not globose-capitate or pistillate inflorescences not multiflorous, tepals and bracts without yellow dye containing glands ..................................................................................... 10

10a. Plants climbers ................................................................................................................................................................................. 11

10b. Plants trees or shrubs ....................................................................................................................................................................... 12

11a. Plants deciduous; lamina chartaceous, leaf margin crenate to serrate-dentate; pistillate inflorescences globose................................ ................................................................................................................... Allaeanthus [ Broussonetia sect. Allaeanthus ] ( A. kurzii )

11b. Plants evegreen; lamina subcoriaceous, leaf margin entire or denticulate towards the apex; pistillate inflorescences capitate but not globose.................................................................................................................... Malaisia [ Trophis sect. Malaisia ] ( M. scandens )

12a. Staminate flowers 5-parted; leaf margin entire ..................................... Pseudostreblus [ Streblus sect. Pseudostreblus ] ( P. indicus )

12b. Staminate flower 4-parted; leaf margin toothed at least toward the apex ........................................................................................ 13

13a. Leaves distichous, spirally arranged, or subopposite: shoot apices shed, just above the upper lateral, scaled resting-bud thorns always absent; pistillate inflorescences spicate or globose, multiflorous ........................................................................................ 14

13b. Leaves distichous; shoot apices persistent, thorns usually present, axillary or terminating short shoots; pistillate inflorescences uniflorous to racemose ........................................................................................................ Taxotrophis [ Streblus sect. Taxotrophis ]

14a. Leaves distichous; pistillate inflorescences spicate; tepals of the pistillate flowers free; stigmas 2 equal ............................... Morus

14b. Leaves spirally arranged or subopposite; pistillate inflorescences globose; tepals of the pistillate flowers connate; stigma 1, or if 2, then unequal ........................................................................................................................................... Broussonetia ( B. papyrifera )