Hillia irwinii Steyerm.

  • Authority

    Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.

  • Family

    Rubiaceae

  • Scientific Name

    Hillia irwinii Steyerm.

  • Description

    Latin Diagnosis - Planta epiphytica ligneosa omnino glabra; stipulis non visis; foliis petiolatis, petiolis 4-10 mm longis, laminis palmatim vel flabellatim nervatis decurrentibus elliptico-ovatis apice abrupte breviter acuminatis 3.5-6.5 × 2-3.5 cm, nervis lateralibus e basi 7-8 exorientibus; floribus terminalibus solitariis pedicellatis, pedicellis in anthesi 7 mm longis in fructu ad 12 mm longis; bracteis sub pedicellis 4 inaequalibus, duabus majoribus late ovatis subacutis 2.5-3 × 2 mm, duabus alternantibus breviori-bus suborbicularibus rotundatis 1.5-2 mm; hypanthio anguste turbinati-cylindrico 18 × 6 mm manifeste stipitato; calycis lobis 10 vel in fructu saepe tantum 6-7 ligulato-linearibus apice rotundatis 8-11 × 1.5-2.2 mm demum deciduis; corolla viridi infundibuliformi 5 cm longa, tubo 4.1 cm longo, inferne parte angustiore 1.6 × 1.1 cm superne ampliato ad 2.5 cm longo fauce 2.2 cm lato, lobis 8 suborbicularibus apice manifeste profundeque emarginatis 10 × 9-10 mm; staminibus 8 paulo exsertis, antheris anguste oblongis apice basique rotundatis 9 × 3.5 mm sessilibus corolla ad aut sub sinubus affixis; stylo 4.2 mm longo glabro, stigmatibus 2 suborbicularibus rotundatis 1 mm longis; capsulis maturis cylindricis 11 cm longis striatis verruculosis; seminibus numerosissimis fusiformibus 1.5-2 mm longis alveolato-verruculosis apice cum penicillio usque ad 17-20 mm longum.

  • Discussion

    Type. Rio Jari, near Cachoeira Macacoara, 0° 53' N, 53° 21' W, Territorio Amapa, Brazil, alt 200 m, 26 Aug 1961, epiphyte on branch of tree overhanging water, W. A. Egler & H. S. Irwin 46683 (holotype NY).

    Paratype. Wilhelmina Gebergte, forested lower slopes of Frederik Top, 3 km south of Juliana Top, 3° 36'-3° 41' N, 56° 30'-56° 34' W, Suriname, alt 500 m, 21 Aug 1963, fleshy-leaved epiphyte on tree 20 m above ground, Irwin, Prance, Soderstrom & Noel Holmgren 54944.

    This taxon is related to H. viridiflora Kuhlm. & Silv. and H. ulei Krause, from which species it may be differentiated by the longer corolla with emarginate corolla lobes, 10 instead of 5-8 calyx lobes, longer anthers, and in the calyx lobes only 1/4-1/5 the length of the corolla instead of 1/3s the length as in H. ulei or 1/3-3/8 the length as in H. viridiflora. In the dimensions of the corolla it more closely resembles H. ulei.