Xerophyte

Central Spines

1-6, sometimes absent, fine, needle-like, nearly erect, reddish brown to yellow, 3-7 mm long. The principal one slightly declined, stout, 3 to 5 mm long.

Seeds

2 mm long and 1mm wide, dark brown to black and minutely pitted.

Description

Mammillaria deherdtianaSN|5387]]SN|5387]] is a compact globe-like plant with large, deep-red flowers that originates from the high mountains of Oaxaca. Plants are solitary. Two subspecies are recognized, the nominate and ssp. dodsonii (Bravo) D.R.Hunt. The distinctions between the subspecies are somewhat ambiguous and even if it appears that there is some geographic separation between them, field studies have established a seamless transition between Mammillaria deherdtianaSN|5387]]SN|5387]] and M. deherdtiana ssp. dodsonii. The standard M. deherdtiana has more numerous spines, usually including 1 or more straight, reddish-brown centrals. Both M. deherdtiana and M. deherdtiana ssp. dodsonii are wonderful, large-flowered and with attractive spination, but fairly slow growing. They flower in summer.

Roots

Thickened fibrous from the basal portion of stem, but lacking the tuberous tap root.

Tubercles

Conical, up to 19 mm long, dark green, in 8 and 13 spirals with watery sap. Axils slightly woolly or naked.

Flowers

Long funnelform, opening widely, bright rose violet, to 50 mm in diameter. Floral tubes long, to 20 mm long, flesh coloured, with small olive green scales, the ovary embedded in the stem between the tubercles. Outer perianth segments up to 10 mm. long, lanceolate, flesh coloured on the margins and greenish in the middle. Inner perianth segments up to 23 mm. long and 4 mm wide, oblanceolate with acuminate tips, bright rose-violet, with a darker mid-stripe and tip. Style, longer than the stamens, white, flushed slightly with violet at the base and beneath the white mid-stripe and tip. Style, longer than the stamens, white, flushed slightly with violet at the base and beneath the white stigma lobes, which are four in number. Filaments erect, the same colour as the style; anthers egg yolk yellow.

Stem

Solitary, depressed globose, to 2-5 cm high and 4.5-5 cm in diameter.

Radial Spines

20-36, fine, needle-like, yellow, becoming white, 3-6(-20) mm long.g, the upper ones slightly curved, the lower ones directed forward and occasionally curving laterally upward or downward, longer and stouter. Light yellow at first but soon passing to a glistening white with occasional reddish brown tips.

Fruits

Globose, 3 to 4mm. in diameter, half embedded in stems, white at the base, the exposed portion pale green, with the dried perianth persisting.

Areoles

Obovate, 4 mm long and 2 mm. wide, covered with pure white felt, , set obliquely at the top of the tubercle. In the case of new areoles the upper half bears minute reddish brown deciduous bristles. Naked or with traces of white wool.