Notocactus Information Exchange - Classification of the Genus Notocactus

Note: I have tried to give links to most definitions of technical words found in these documents. However, to reduce the file size and increase layout speed, I have only put one link, for each word, in each section, ie. if the word Areole is found more than once in a description of a section, then only the first occurrence will have a link to its definition.
A description of the position of the genus Notocactus within the Cactaceae is also available.

General classification

The genus Notocactus has been subdivided into smaller groups to aid the understanding of relationships between these groups. These subdivisions are formed on the basis of body form, flower structure, fruit forming characteristics, distribution etc.

In most cases these sub groupings are split further to identify relationships within them. These subdivisions are given specific terms: genus is the top level in relation to Notocactus, subgenus is the next level down, section the next, then going lower down we get to series, species, variety and the bottom level is form. For instance if you have a plant of Notocactus ottonis var. paraguayensis fa. Yhaguy Guazu. This would have the following subdivisions:

Genus:	Notocactus
Subgenus:	Notocactus
Section:	Paucispini
Series:	Ottonis
Species:	Ottonis
Variety:	Paraguayensis
Form:	Yhaguy Guazu (ie. from Yhaguy Guazu in Paraguay)

This document (which is mainly a translation from Die Gattung Notocactus by Gerhardt Schäfer) explains the subdivisions down to the level of Section; links to discussions of further subdivision will be found when relevant and if available.

Subgenus Notocactus sensu Buxbaum

The description of the Subgenus Notocactus given by Buxbaum is incomplete. He left out the characteristics of Series 2 of Section I Paucispini Fric.

Very variable in habit. Flower narrow to wide funnel shaped, in some plants widening to form a bell shaped receptacle , the pericarpel mostly densely covered with scales. The areoles in the scale axils mostly bear copious wool, but can also be completely without wool. In addition hair like spines exist, or only the spines of the uppermost areoles are hair like, the lowest however are stiff and piercing (in N. apricus). Two stamen groups usually recognizable. The fruits are always at first soft fleshed, later drying out. The seeds are short to extended bell shaped with a blackish, rough humpy testa. The hilum seam is often curved, the hilum is approximately round, wide or narrow oval, almost straight to somewhat convex with a more or less clearly defined micropylar mound.

Section I -- Paucispini Fric

Series 1 and 3 correspond to the description by Buxbaum for the Subgenus but in Series 2 there are many differences in the development of the flower, members of Series 2 possess a wide cup to bell shaped receptacle, which at least in the early bud stage, there is no woolly hairs or the plants show a strong reduction of the wool hairs. The plants are globose, later often somewhat elongated, strong green to shiny light yellow green. Spines not numerous or dense, needle like to somewhat curved, light yellow to red brown. Almost all species form offsets at the base; some species share the characteristic of underground offset formation (N. ottonis, N. megapotamicus, N. linkii), this is also a typical feature of representatives of Section II (Fricianae).

The species in section I are spread over the entire range of the genus Notocactus in countless varieties and forms.

Section II -- Fricianae Havlicek

Plants dwarf, cylindrical, hardly 3 cm high; (in cultivation becoming bigger, particularly when grafted). Roots turnip like, from which underground offsets form (see also Section I). Ribs 12-15; Radial spines white ca. 15; Central spines 3-4, brown to red brown, some bent to hooked. Flower yellow, ca. 5 cm (-7 cm) Ø; ). Stamens in two groups, sensitive, plants self sterile.

Section III -- Scopanae Havlicek

The species of section III are characterized by very numerous, fine bristle to fine needle like, white, yellow or red spines; Ribs very numerous. Plants solitary or strongly offsetting and later cushion forming, globose to long and thin cylindrical; apex slightly sunken and covered by the spines of the young areoles. Flower with funnel shaped receptacle; stamens in two groups, pistil typically red coloured, stigma red; stamens sensitive; plants self sterile. Fruit formation not typical of the other sections of the Subgenus Notocactus. The ripening berry opens horizontally in the lower third, leaving a bowl in which the seeds sit.

Section IV -- Werdermannianae Havlicek

Plants mostly solitary, only rarely offsetting, inverted pear shaped, apex somewhat sunken, sparsely covered with white wool. Ribs numerous to about 40, with small chin like humps; Areole sunken between the humps. Spines very numerous, strong variation in the colouration, from almost white to dark brown. Flower medium sized to large with funnel shaped receptacle, petals yellow; stamens in two groups, sensitive; Plants self sterile. Fruit formation typical for the section; the fruit opens on top, directly under the flower remains.

Section V -- Setacei Fric

Plants rarely offsetting, broad globose, later also short columnar, light to blue green; apex somewhat sunken, naked or covered by the spines of the young areoles. Ribs 15-30, blunt, low, straight or somewhat spiralling; all spines flexible, thin, bristle like; Central spines 4-6, reddish yellow to brown red or horn coloured, partly bent downwards; Radial spines to 25, yellowish grey to water pale, sideways spreading and often somewhat interlinked together. Flower medium sized to large, yellow; pericarpel somewhat stretched, with a more or less clear cut constriction of the flower base. Receptacle funnel shaped; stamens in two groups, as a result of the constriction of the flower base they are difficult to differentiate, not sensitive; plants partially self fertile.

Section VI -- Uebelmannianae Havlicek

Plants remarkably like a Gymnocalycium, broad globose, always solitary, to 15 cm and more wide, grass to grey green; apex slightly sunken, somewhat white felted, free from spines. Ribs ca. 16 (and more), divided into humps, often only slightly, or more often pronounced chin like ; areole between the humps. Spines not hard or sharp, mostly horn coloured, new spines also brownish to reddish; Radial spines 10-15, Central spines mostly 1, often pointing downwards. Flower medium sized to very big, yellow, in one case violet to wine red; receptacle funnel shaped, stamens in two groups, not sensitive, Plants self sterile.

Section VII -- Herterianae Havlicek

Plants large, to 20 cm Ø, 30 cm high, globose at first, later columnar, also somewhat offsetting from the base, green to grey green; apex somewhat sunken, when mature covered with short white wool. Ribs 15-25, straight, exceptionally somewhat spiralling, more or less divided into protruding humps. Radial spines 10-15, white to brownish; Central spines 4-6, very variable in colour, from light yellow to brown red. Flower medium sized; receptacle funnel shaped; petals coloured from yellow orange via orange red to wine red; stamens in two groups, sensitive; Plants partially self fertile.

Subgenus -- Neonotocactus sensu Buxbaum

The flowers are noticeably wider, in spite of the thick covering of wool. The wide bowl shaped or at least wide funnel shaped receptacle widening immediately above the pericarpel; at the curve stand the (only) lower stamen group, rising upright from the receptacle and firstly bending towards the pistil, then bending away. The wide bell shaped seed often has a a thick cushion like hilum. The cuticle is divided into tiny star shaped areas,in which the tips of the testa warts sit. Special to this Subgenus is the elongation in the basal section of their fruits in the early ripening stage. Opening with a basal hole.

Section VIII -- Mammulosi Fric

Plants globose to short cylindrical, grey green to dark green, extremely variable in appearance; apex somewhat sunken; Ribs 13-25, mostly sub-divided into prominent chin like humps; areoles wide, wool felted, especially so in the apex, sunken between the humps. Areoles in the apex mostly without spines. Spines hard and sharp. Flower remarkably wide; widening above the pericarpel to form a bell shaped receptacle ; petals shiny gold to lemon yellow; stamens only one group developed, arising from the flower base and cramped around the pistil; no Nectary. Fruit elongating to form a tube, when fully ripe overhangs; basal opening. Seeds with thick cushion like hilum. Stamens not sensitive. Plants self fertile.

Section IX -- Melchersianae Havlicek

Plants more or less elongated globose to short columnar, later to 20 cm high, matt green to dark green; Ribs ca. 20, only slightly humped; areoles sunken in the ribs, more or less strongly felted; apex slightly sunken, covered with the wool and spines of the young areoles; Radial spines to 20 and more, fine needle like, sideways radiating and covering the body, white to yellow; Central spines 1-4, stronger, standing away, horn coloured to red brown. Flower wide to narrow bell shaped, petals yellow to pink carmine; stamens formed into one group, closely fitting the pistil; Nectary visible in several species; Stamens not sensitive, fertilization conditions not uniform.

Subgenus Malacocarpus (S.D.) Buxbaum

Body globose with numerous, very striking sharp ribs, swollen at the areoles, or protruding like warts. Young areoles of mature plants bear an, especially rich covering of wool, the apex completely covered; later the areoles become bare. Flowering from the apex, the flower expanding over the pericarpel to become somewhat bell shaped. The scales of the pericarpel are strongly reduced and bear rich wool, with the receptacle bearing bristles. In the internal structure similar to the flowers of the Subgenus Notocactus, while both stamen groups are more or less distinct. The soft berry like fruit always almost hidden in the apex wool. It bears a wool covering, but can also be absent. The wide bell shaped seeds are covered with the brown, mostly wrinkled, aril skin. The stamens are sensitive, the inner group surrounding the Nectary; with the exception of N. neohorstii and longispinus, the plants are self fertile.

Subgenus Brasilicactus (Backeberg.) Buxbaum

Globose, later becoming elongated, with very numerous ribs, divided by small wart like areoles with very dense, fine spination. Flowers of this Subgenus are typically small, greenish, yellow or orange red arising in great numbers from the apex. They are individually very variable. As a rule the receptacle opens above the pericarpel into a short funnel-bell shape. The wool in the scale axil is relatively short, while the stiff bristle like spine covering is very conspicuous. Consequently the globose fruit is also small, not woolly, but covered with bristles. The strongly warted, black seeds are comparatively small, elongated and somewhat bent. The hilum is wide oval and contains the distinctive micropylar hump. The fertilisation conditions of the numerous species and varieties are still not clear; The type species is self fertile; the stamens are not sensitive.

Subgenus Eriocactus (Backeberg.) Buining

To 1 m high, thick columnar with very numerous ribs and fine, but dense spination. The young areoles are very densely felted, apex often tilted. The impressive wide bell shaped flowers grow from the apex, and are densely covered with wool and dense hair like spines, terminating in scales. The relatively short and thick walled receptacle opens over the pericarpel without transition to become a wide bell shape. Above the ovary it narrows towards the style to form a small nectary, so that a small step develops, from this arise the lower stamen group. The upper stamen group arise from the bell shaped part. The short fruit is densely covered with wool and bristled, dry and opens horizontally at the base. The very small numerous seeds are more or less narrow conical, approximately hat shaped, the large basal hilum bears the micropylar hole in the centre. The testa is dark brown, covered with fine warts. The stamens are not sensitive. The fertilization conditions differ according to species.

Subgenus Brasiliparodia Ritter

Body: Globose, somewhat elongated when mature, softer than in Notocactus, apex not tilted, depressed, fibrous roots. Ribs: Quite numerous, only a few mm high, more or less deeply notched, with rounded tuberculate humps. Areoles: With white wool, plump, on the top of the hump, close together. Spines: Quite numerous, needle to bristle like, more or less straight, flexible, the central spines somewhat stronger and darker, the lowest 1-4 mostly strongly hook like. Flower: From the apex, medium sized to quite small, the wall thick, flower remains persistent. Ovary: Somewhat wider than long, green, scales more numerous than in Notocactus, very small, pointed mostly somewhat shell like at the end, thick wool and some fine bristles in the axil. Nectar Chamber: Very small, with very little nectar. Receptacle: Funnel to funnel-cup shaped, yellow inside, more green outside, covering similar to the ovary. Stamens: Yellow, thin, inserted over the whole of the receptacle, standing at different heights, anther yellow, small. Pistil: Yellow, short, not opening much, stigma lobes mostly stand above the stamens. Petals: Oblanceolate to more linear, at the base only slightly narrowing, top rounded to pointed, moderately large, inside always yellow, outside mostly somewhat reddish, opens in the morning for several days, closing after midday. Fruit: Globose, mostly green, rarely red, covered as the ovary, soft, thin walled, usually dries up on the plant without opening. Seed: Very similar to that of Brasilicactus, but shorter. Distribution: In the higher, coastal mountainous locations of North-Eastern Rio Grande do Sul and Santa Catarina on rocky places.

Transitional Species

In the framework of this division of the extremely variable plants of the genus Notocactus into various subgenera there are plants which do not fit into a specific Subgenus. These plants are considered to be connecting links between the various subgenera and sections.

According to Van Vliet N. roseoluteus is a transitional form between N. mammulosus and N. herteri, thus forming a connecting link between the Subgenus Neonotocactus (section VIII Mammulosi) and the Subgenus Notocactus (section VII Herterianae), in which the characteristics of N. herteri predominate.

Also N. schlosseri is such a connecting link between N. mammulosus (Subgenus Neonotocactus section VIII Mammulosi) and N. scopa (Subgenus Notocactus section III Scopanae).

N. buiningii standing very near to N. mammulosus (Subgenus Neonotocactus section VIII Mammulosi), also possesses some characteristics of the Subgenus Malacocarpus.

Also interesting is the fact that the 3 previously mention plants have very similar characteristic flowers with a bell shaped receptacle , a Nectary and very numerous stamens that extend into the gullet of the flower. An additional difficult to assign transitional form of the Subgenus Malacocarpus is N. allosiphon. This plant was incorrectly placed into the Subgenus Neonotocactus by Marchesi.

Finally are N. rauschii and N. fuscus. They possess flowers very similar to N. scopa (Subgenus Notocactus section III Scopanae); the stamens are in two groups and are sensitive and the plants are self fertile. However there fruit formation is reminiscent of N. mueller-melchersii (Subgenus Neonotocactus section IX Melchersianae), i.e. the fruit starts off being berry shaped and then ripens to become tubular. These plants are also closer in habit to N. mueller-melchersii. There is little use in placing all these plants in a special group. For the present it seems that research into these transitional forms is better.

Classification of the genus Notocactus Sensu Buxbaum

General classification

Subgenus Notocactus sensu Buxbaum

Section I -- Paucispini Fric

Section II -- Fricianae Havlicek

Section III -- Scopanae Havlicek

Section IV -- Werdermannianae Havlicek

Section V -- Setacei Fric

Section VI -- Uebelmannianae Havlicek

Section VII -- Herterianae Havlicek

Subgenus -- Neonotocactus sensu Buxbaum

Section VIII -- Mammulosi Fric

Section IX -- Melchersianae Havlicek

Subgenus Malacocarpus (S.D.) Buxbaum

Subgenus Brasilicactus (Backeberg.) Buxbaum

Subgenus Eriocactus (Backeberg.) Buining

Subgenus Brasiliparodia Ritter

Transitional Species