Archivos de diario de noviembre 2023

10 de noviembre de 2023

Species description: Euchaetis albertiniana & Euchaetis burchellii

SA Journal of Botany
Studies in the Genera of the Diosmeae (Rutaceae): 10
.......Full reference to follow......

Euchaetis albertiniana

  1. Euchaetis albertiniana Williams in J1 S. Afr. Bot. 41 (3): 167 (1975). Type:
    CAPE 3421-(Riversdale): Near Askop on south side of road 16 km west of
    Albertinia (-AB), 180 m alt., 2/3/1974, Williams 1879 (NBG, holotype; K, PRE,
    STE, isotypes).

Euchaetis albertiniana is recognised as distinct from E. burchellii Dümmer in
that it is destroyed by fires whereas E. burchellii develops a stout rootstock from
which it may regenerate after fires - a character seldom noted on herbarium
sheets. However, the leaves in E. albertiniana are often adpressed, ciliolate with
an apical callus, whereas those of E. burchellii are never so. The anther in E.
albertiniana possesses a small pointed gland, but that of E. burchelli is minute
E. albertiniana differs frọm E. laevigata Turcz. which has leaves complicate
orbicular, spreading and somewhat more recurved towards the apex with the
apical gland on the anther minute as in E. burchelli, E. albertiniana is found in
the vicinity of Albertinia. E. burchelli is more widespread being found in sandy
soil from beyond Great Brak River in the east to Uilenkraal River near Gans
baai in the west.

Euchaetis burchellii

  1. Euchaetis burchellii Dümmer in Kew Bull.: 90 (1912)
    Type: CAPE--3422 (Mossel Bay): sandy hills near the landing place, Mossel
    Bay (on shrubby sandy dry hills close to our station near landing place Mossel Bay), 18/10/1814, Burchell 6239 (K, holotype).

Shrubs to 1 m tall forming a dense bush with many stems arising from a stout rootstock. Branches short, fairly erect, bark scaly and rough. Branchlets numerous, slender, very short, puberulous, well-clothed with leaves. Leaves to 4,5 mm long, 1,5 mm broad, lanceolate, obtuse without any mucro, sub-trigonal, glabrous, eciliate, sessile, opposite, erect, sub-imbricate, decussate, about twice times longer than the internodes. Inflorescence terminal, usually twin, white or pink. Bract one to each flower, 1,9 mm long, 1,3 mm broad, ovate, obtuse, glabrous, thickened toward the apex, sessile, very sparsely ciliate, midrib 1-2 gland-dotted. Bracteoles two, 1,6mm long, 0,8 mm broad, elliptic, obtuse, glabrous, apex thickened; margins broadly translucent, ciliolate. Calyx lobes five, 2mm long, 1,5-2 mm broad, roughly orbicular, glabrous; apex blunt, trigonal, green; margins broadly translucent, ciliolate. Petals 3.7- 4 mm long, 2,5 mm broad; limb orbicular, 1-2 gland-dotted; claw transversely bearded, midrib pubescent, margins ciliate. Staminodes vestigial, 0,15 mm long, 0,1 mm diam. Filaments 5, 1,3 mm long, pale, acicular. Anthers five, 0,6 mm long, wine-coloured; apical gland minute. Pollen 52 micron long, 32 micron broad, ellipsoid with three longitudinal grooves. Disc closes over the ovary at first. Stigma 0,5 mm diam., globose, capitate. Style becoming 1,5 mm long, erect, persisting. Ovary 5-carpellate, 0,7 mm diam., with a few hairs at the sides towards the apex of each segment. Fruit 5-carpellate, 6 mm long overall, glabrous, gland-dotted; horns 1,2 mm long, clasping a gland at the tip. Seed 4,2 – 4,8 mm long, 1,8-2 mm broad, black, shining; aril white.

Euchaetis burchellii is a lowland coastal species found growing in stabilised
wind-blown sand never very far from the sea, at altitudes of from 33 to 250
metres above sea level. Its geographical range extends from Herolds Bay near
George in the east to the Uilenkraals River near Gansbaai in the west, a dis-
tance of about 275 km.

It is a dense shrub with many stems arising from a stout rootstock, having
leaves lanceolate, obtuse, eciliate, without any apical callus and never adpressed.

It is perhaps closest to E. albertiniana Williams which however is a fairly
diffuse shrub, single-stemmed at base with leaves sometimes adpressed and with
a small apical callus. It differs from E. laevigata Turcz. which has leaves sub-
complicate, orbicular and spreading and is found growing upon limestone to the
east of Bredasdorp

Publicado el noviembre 10, 2023 12:20 TARDE por sandraf sandraf | 1 comentario | Deja un comentario