Mammillaria vorwerkii
Hauptverz. 1937, 9, nomen.
Family
Cactaceae
Genus
Species
Mammillaria vorwerkii
Author
(Frič) Graessn.
Chinese genus
乳突球属
Chinese name
-
Primary
Accepted
DescriptionEdit description
Central Spines
1-3, often hooked, whitish, brownish to grayish, to 2(-4) cm long.
Seeds
Blackish to brown, large, 2.2 x 1,4 mm, rugose, broadly oval or shaped like a comma, ruminate; border expanded around hilum; cells gradually smaller towards hilum. Hilum inconspicuous.
Description
Neowerdermannia vorwerkiiSN|10426]]SN|10426]] has the form of an inverted cone with the flat top almost at soil level, but in cultivation it usually shows a spherical shape, bearing flowers almost laterally. The fat underground stock is formed by part of the stem (identifiable from the remnants of old areoles) merging with the tuberose root (identifiable from the fine lateral roots). The spines are brownish, spreading star-like from the areoles. The flower is white with a lilac midrib to the petals, and scaly but bare with distinct nectar chamber. The genera Gymnocalycium and Weingartia are very similar, but the areoles of Neowerdermannia are located in the depressions between the tubercles and the tiny fruit contain very few seed.
Roots
Thick turnip-like.
Flowers
Almost lateral, funnel-shaped, tepals white or pale lilac-pink with a darker midline, 15-20 mm long and in diameter, bare (without hairs) but scaly and with a distinct nectar chamber.
Blooming Season
May or June.
Ribs
16 or more, indistinct, spiralling, deeply divided into bluntly conic tubercles, 3-sided, with a triangular flattened upper side, and an acute, hatchet-like under side.
Stem
Depressed globose, partially underground, green, pale green or dark grey-green, 6-8(-10) cm across.
Fruits
Deep seated between the tubercles, globose, green, becoming reddish, 5-8 mm in diameter. Opening when ripe by a partial circumscissile splitting near the top of the fruit with the partial fruit cap tilting outward at about 160°. The fruit mature the year after.
Areoles
Found, uncharacteristically for cacti, at the base of the tubercles instead of at the apex and with white-wool when young.Radial spines Up to 10 spreading star-like, curved, blackish at first, later whitish or brownish, to 17 mm long. Lowest directed downward.