Porpax williamsonii (P.J.Cribb) Schuit., Y.P.Ng & H.A.Pedersen, Bot. J. Linn. Soc. 186: 201 (2018).
Homotypic Names:
Stolzia williamsonii P.J.Cribb, Kew Bull. 33: 88 (1978).
Description:
A dwarf creeping epiphytic herb. Pseudobulbs 2-leaved, narrowly long-clavate, horizontal, appearing rhizomatous, swollen below leaves only, 2-4 cm. long, 1 2 mm. diameter. Leaves thin-textured, spreading, obovate to elliptic-obovate, rounded a apex, shortly petiolate, 1-2 cm. long, 0.5-0.9 cm. broad, articulated 1 mm. above apex of pseudobulb. Inflorescence 1-flowered, much shorter than leaves peduncle up to 3 mm. long; bract ovate-elliptic, acute, 1.5 mm. long. Flower large for size of plant non-resupinate, red-brown. Dorsal sepal concave, narrowly oblong-elliptic, obtuse 8.5 mm. long, 3 mm. broad; lateral sepals obliquely ovate-elliptic, obtuse, united for basal one-third, 7-7.5 mm. long, 3 mm. broad; mentum saccate, 2-2 5 mm. long Petals oblong-elliptic, obtuse, papillose, 7 mm. long, 2 mm. broad Lip recurved, narrowly clawed, lanceolate-ligulate, acute or acuminate, 3 5 mm. long.
Etymology:
After Graham Williamson (1932- ), Zimbabwean dental surgeon and collector, particularly of orchids, in Zambia and Malawi. He first found and described many species and is the author of Orchids of Central Africa (1977).
Habitat:
Epiphyte in montane forest; 2150-2900 m.
Flowering time:
Feb - Mar
Distribution:
Rwanda to N. Malawi
References:
Flora of Tropical East Africa: Orchidaceae, Part 2; Cribb, P.J. (1978). A revision of Stolzia (Orchidaceae) Kew Bulletin 33(1) Page 88.; La Croix, I. et al. (1991). Orchids of Malawi A.A. Balkema, Rotterdam Page 185.; La Croix, I. & Cribb, P.J. (1995). Orchidaceae (Part 1) Flora Zambesiaca 11(1) Page 291.
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Porpax viridis (P.J.Cribb) Schuit., Y.P.Ng & H.A.Pedersen, Bot. J. Linn. Soc. 186: 200 (2018).
Homotypic Names:
Stolzia viridis P.J.Cribb, Kew Bull. 33: 87 (1978).
Description:
A creeping epiphytic herb to 15 cm. high. Pseudobulbs obliquely ovoid-fusiform, to 2.5 cm. long and 1.5 cm. high, 2-leaved at off-centre apex. Leaves ligulate to elliptic-oblong, erect, bright green, to 12 cm. long and 1.7 cm. wide, rounded and emarginate at apex. Inflorescence ± equal to leaves, erect, densely 6-14-flowered, to 11 cm. long; peduncle flattened, 3-5 cm. long; bracts lanceolate, 0.7 cm. long, acute to acuminate. Flowers secund, lime-green with a purple lip. Dorsal sepal ovate-elliptic, 0.6 cm. long, 0.3 cm. wide, obtuse, margin slightly ciliate; lateral sepals similar but obliquely ovate and acute, fused to each other in basal half and forming a saccate mentum with the column-foot. Petals narrowly elliptic, 0.4 cm. long, 0.2 cm. wide, rounded, margin obscurely ciliate. Lip ovate when flattened, fleshy, sulcate at base, 0.25 cm. long, 0.15 cm. wide, rounded at apex. Column truncate, 0.15 cm. long; rostellum broad, flap-like; stigma orbicular; anther-cap rounded, verrucose.
Habitat:
On mossy branches in wet mist forest; 1600-2000 m.
Distribution:
Tanzania (Uluguru Mts.)
References:
Flora of Tropical East Africa: Orchidaceae, Part 2; A revision of Stolzia (Orchidaceae) Kew Bulletin 33(1) Page 88.
Images:
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Porpax repens var. repens
Description:
A small epiphyte. The widely creeping, prostrate, stems like pseudobulbs can form extensive mats, sometimes covering entire trunks and branches of the host trees. Leaves 2 per pseudobulb, suborbicular. Flowers solitary yellow with darker brown-yellow stripes.
Habitat:
In Brachystegia woodland at higher altitudes, 1050 - 2200 m.
Phenology:
Flowering in Dec. - Feb
Notes:
It differs from the rare and restricted Stolzia repens var. obtusa by the much lighter coloured flowers and the longer, lanceolate and acuminate petals and sepals.
Distrubtion:
Burundi, Cameroon, Equatorial Guinea, Ethiopia, Ghana, Kenya, Liberia, Malawi, Mozambique, Nigeria, Sudan, Tanzania, Uganda, Zambia, Zaïre, Zimbabwe.
References:
Summerhayes, V.S. (1953). African orchids XXI Kew Bulletin 8(1) Page 141.; La Croix, I. et al. (1991). Orchids of Malawi A.A. Balkema, Rotterdam Page 184.; La Croix, I. & Cribb, P.J. (1995). Orchidaceae (Part 1) Flora Zambesiaca 11(1) Page 290.; Cribb, P.J. (1978). A revision of Stolzia (Orchidaceae) Kew Bulletin 33(1) Page 87.
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Porpax repens var. obtusa (G.Will.) Schuit., Y.P.Ng & H.A.Pedersen, Bot. J. Linn. Soc. 186: 200 (2018).
Homotypic Names:
Stolzia repens var. obtusa G.Will., J. S. African Bot. 46: 333 (1980).
Description:
Flowers red-brown with 2 yellow stripes at the base of dorsal sepal and petals. Dorsal sepal 5 × 1.5 mm, oblong, obtuse, projecting forwards; lateral sepals 5 × 1.2 mm, deflexed, falcate-lanceolate, obtuse; mentum saccate, somewhat bent forwards. Petals spreading, 4 × 1 mm, oblong, obtuse. Lip c. 2 mm long.
Habitat:
Montane and submontane evergreen forest, epiphytic on mossy branches c. 2000 m.
Notes:
This variety differs from Stolzia repens var. repens in the more rounded shape of the petals and sepals, and dark red-brown flowers with lighter stripes on the petals and sepals. It often has slightly larger and less succulent leaves, possibly due to its moister and more sheltered habitat in montane evergreen forest.
Distribution:
Rwanda to E. Zimbabwe
References:
La Croix, I. & Cribb, P.J. (1995). Orchidaceae (Part 1) Flora Zambesiaca 11(1) Pages 290 - 291.
Images:
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Habitat/In situ | Flower close up |
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Photograph©Bart Wursten. Image used with kind permission. |
Photograph©Bart Wursten. Image used with kind permission. |
Porpax repens var. cleistogama (Stévart, Droissart & M.Simo) Schuit., Y.P.Ng & H.A.Pedersen, Bot. J. Linn. Soc. 186: 200 (2018).
Homotypic Names:
Stolzia repens var. cleistogama Stévart, Droissart & M.Simo, Adansonia, sér. 3, 31: 30 (2009).
Description:
Herbe épiphyte, rampante, glabre, atteignant 20 cm de longueur. Pseudobulbes bifoliés de 1,5-2,5 cm de longueur et jusqu’à 1,8-2,5 mm de diamètre, épaissis sur 2 à 3,5 mm au niveau de l’insertion des feuilles. Racines glabres, charnues, de 0,7 mm de diamètre. Feuilles circulaires à oblongue-obovales, planes à apex retus à obtus, charnues, 3-8 × 2,5-5 mm, situées juste au dessus de l’insertion du pseudobulbe suivant. Infl orescence unifl ore ; pédoncule cylindrique atteignant 1 mm de longueur et 1 mm de diamètre ; pédicelle et ovaire d’environ 1 mm de longueur, couverts de deux bractées triangulaires engainantes de 0,7 mm de longueur. Fleur uniformément jaune-verdâtre, devenant entièrement rouge avec l’âge. Sépale médian obovale, à apex obtus et légèrement subapiculé, 3-nervé, 3-3,5 × 1,5 mm, concave à l’apex, non réfl échi. Sépales latéraux obliquement ovale-elliptiques, 3-nervés à apex obtus et subapiculé, légèrement carénés à l’apex sur 1 mm, 3,5 × 2-2,5 mm, non réfl échis, soudés en un mentum de 1 à 1,5 mm et avec le sépale médian sur 1,5 à 1,8 mm. Pétales lancéolés, à apex obtus, 3- nervés, non réfl échis, 2,8 × 1,8 mm. Labelle entier, dépourvu de callus, 2,2 × 1,2 mm (étalé), elliptique à spathulé, à apex obtus et marges entières, à nervure centrale proéminente. Colonne de 2 mm de longueur, 8 pollinies obovoïdes de 0,3 × 0,1 mm. Loge pollinique de 0,5 mm. Fruit presque sphérique de 3 mm de diamètre.
Etymology:
Ce nouveau taxon doit son nom à la morphologie de ses sépales qui explique que la fl eur ne s’ouvre pratiquement pas et garde donc l’aspect d’un bouton non épanoui.
Habitat:
Épiphyte sur Psydrax parvifl ora (Afzel.) Bridson subsp. parvifl ora (Rubiaceae) sur une branche de 3-4 cm de diamètre couverte de mousse à une hauteur d’environ 1,2 m du sol dans le manteau arbustif d’un inselberg. L’espèce y fut collectée avec deux autres Orchidaceae, Angraecum eichlerianum var. curvicalcaratum Szlach. & Olszewski et Polystachya tessellata Lindl., ainsi qu’une Lentibulariaceae, Utricularia mannii Oliv.
Distribution:
W. & WC. Cameroon
References:
Le genre Stolzia (Orchidaceae) en Afrique centrale avec deux nouveaux taxons, ADANSONIA, sér. 3 • 2009 • 31 (1)
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