RECORD: Hooker, J. D. 1846. Description of Pleuropetalum, a new genus of Portulaceae, from the Galapagos Islands. London Journal of Botany 5: 108-9.

REVISION HISTORY: Scanned by John van Wyhe, transcribed (single key) by AEL Data 6.2008. RN2


[page] 108

Description of PLEUROPETALUM, a new genus of PORTULACEÆ, from the GALAPAGOS ISLANDS; by J. D. HOOKER, R. N. M. D. F. L. S.

TAB. II.

CHAR. GEN.—Calyx dipsepalus, persistens, sepalis basi connatis. Corolla 5-petala, petalis hypogynis ovatis concavis coriaceis dorso multi-costatis, æstivatione imbricatis. Stamina 8; filamenta infra medium monadelpha; antheræ biloculares, erectæ longitudinaliter dehiscentes. Ovarium liberum, globosum, uniloculare. Ovula plurima, placentæ basilari funiculis distinctis elongatis inserta, amphitropa. Stylus brevissimus. Stigmata 4 paulo divaricata, teretia. Capsula—?

[page] 109

Suffrutex(?) Galapagæus erectus, glaberrimus, ramis teretibus, superioribus foliosis. Folia integerrima. Flores in racemos terminales lateralesve dispositi, breviter pedicellati.

1. PLEUROPETALUM Darwinii, Hook. fil. in trans. Soc.

Linn. Lond. ined.— (Tab. Nostr. II.)

HAB. James Island, Galapagos; C. Darwin, Esq.

Rami cylindracei, teretes, crassitie pennaæ cervinæ, ramulis foliiferis breviusculis. Folia alterna, petiolata, 2–3 unc.longa, 1–1½ lata, anguste ovato-lanceolata, utrinque attenuata longe acuminata, integerrima, costa venisque conspicuis, petiolo ¼ unc. longo. Racemi subunciales, 5–7 flori, pedicello valido tereti superne florifero. Flores breviter pedicellati, sub 3 lin. lati, pedicello crasso tereti. Calycis foliola ovata, acuta, concava, petalis 1/3 breviora. Petala ovata, subacuta,concava, siccitate coriacea, dorso præcipue costis plurimis parallelis percursa, erecto-patentia. Stamina infra medium in cupulam membranaceam coalita, filamentis anguste subulatis. Ovarium globosum, subcarnosum. Stigmata paulo divaricata, subobtusa.

A very distinct genus, of which I have seen only the specimens gathered by Mr. Darwin during the visit he paid to these curious islands in H.M.S. Beagle. The habit of the plant is somewhat like that of Rivina.

TAB. II.—Fig. 1. Bud, pedicel and bractea; fig. 2. a flower expanded; fig. 3. the same with the petals removed; fig. 4. ovarium;—all magnified.

[Tab II]

Pleuropetalum Darwinii


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Citation: John van Wyhe, editor. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

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