| Orchidaceae | |
Houlletia antioquiensis
| (André) L.H. Bailey | Stand. Cycl. Hort. 1608 | 1915 |
| Orchidaceae | |
Houlletia boliviana
| Schltr. | Repert. Spec. Nov. Regni Veg. 27(726/733): 65 | 1929 |
| Orchidaceae | |
Houlletia brocklehurstiana
| Lindl. | Edwards's Bot. Reg. 27: Misc. 47 | 1841 |
| Orchidaceae | |
Houlletia buchtienii
| Kraenzl. | Repert. Spec. Nov. Regni Veg. 25(681/683): 28–29 | 1928 |
| Orchidaceae | |
Houlletia chrysantha
| L. Linden & André | Ill. Hort. 18: 138, t. 171 | 1871 |
| Orchidaceae | |
Houlletia clarae
| Schltr. | Repert. Spec. Nov. Regni Veg. Beih. 27: 81 | 1924 |
| Orchidaceae | |
Houlletia conspersa
| P. Ortiz | Orquideología 19(3): 4 | 1994 |
| Orchidaceae | |
Houlletia juruenensis
| Hoehne | Comm. Lin. Telegr., Bot. 5(1): 47–49, t. 38 | 1910 |
| Orchidaceae | |
Houlletia kalbreyeriana
| Kraenzl. | Notizbl. Bot. Gart. Berlin-Dahlem 7: 434 | 1920 |
| Orchidaceae | ** |
Houlletia landsbergii
| Linden & Rchb. f. | Gartenflora 1855: 2 | 1855 |
| Orchidaceae | |
Houlletia lansbergii
| Linden & Rchb. f. | Gartenflora 4: 2–3, t. 108 | 1855 |
| Orchidaceae | |
Houlletia lowiana
| Rchb. f. | Gard. Chron., n.s. 2: 484 | 1874 |
| Orchidaceae | |
Houlletia luteoflora
| Roias. | Cat. Hist. Nat. Corrient. 83 | 1897 |
| Orchidaceae | |
Houlletia odoratissima
| Linden ex Lindl. & Paxton | Paxt. Fl. Gard. 3: 172 | 1853 |
| Orchidaceae | |
Houlletia picta
| Linden & Rchb. f. | Gartenflora 4: 2 | 1855 |
| Orchidaceae | |
Houlletia roraimensis
| Rolfe | Trans. Linn. Soc. London, Bot. 6: 63 | 1901 |
| Orchidaceae | |
Houlletia sanderi
| Rolfe | Gard. Chron., ser. 3 47: 206 | 1910 |
| Orchidaceae | |
Houlletia stapeliaeflora
| Brongn. ex Lem. | Ill. Hort. t. 612 | 1869 |
| Orchidaceae | |
Houlletia stapeliiflora
| Brongn. | Hort. Universel 3: 132 | 1841 |
| Orchidaceae | |
Houlletia stapelioides
| Brongn. ex Rchb. f. | Gartenflora 2 | 1855 |
| Orchidaceae | |
Houlletia tigrina
| Linden ex Lindl. & Paxton | Paxt. Fl. Gard. 3: 171–172 | 1853 |
| Orchidaceae | |
Houlletia unguiculata
| Schltr. | Repert. Spec. Nov. Regni Veg. Beih. 7: 160 | 1920 |
| Orchidaceae | |
Houlletia vittata
| Lindl. | Edwards's Bot. Reg. 27, Misc. 47, no. 100: t. 69 | 1841 |
| Orchidaceae | |
Houlletia wallisii
| Linden & Rchb. f. | Gard. Chron. 661 | 1869 |