M. gracilis (slender).--A small Thimble Cactus, remarkable for its proliferous stems, a single stem 2 in. high producing all round its upper half numerous, offshoots, which fall to the ground and grow. In this way a tuft of stems is soon developed round the first one. If these offshoots are removed as they appear, the stem will grow longer and stouter than it does when they are left. Tubercles small, green, crowded; spines in a stellate tuft, short, curved, pale yellow or white.

Flowers as in M. elongata, to which this species is closely allied. In window cases, or on a shelf in a cool greenhouse, it will grow and multiply rapidly. Like the bulk of the caespitose, or Thimble Cactuses, it does not make much show when in flower; and it is only its stems, with their white stars of spines and cl.u.s.ters of little offsets hanging about them, that are attractive. Native of Mexico; introduced about 1850. There is a variety known as pulch.e.l.la, in which the spines are of a yellow hue.

M. Grahami (Graham's).--A pretty little species, with globose stems, scarcely 3 in. high, and nearly the same in diameter, branching sometimes when old; tubercles in. long, egg-shaped, corky when old, and persistent. Spines in tufts of about twenty, all radiating except one in the centre, which is hooked; they are about in. long. Flowers 1 in.

long, usually produced in a circle round the stem. Fruit a small, oval berry, in. long. This is a native of Colorado, in mountainous regions.

It is very rare in cultivation. The flowers are developed in June and July.

M. Haageana (Haage's); Fig. 62.--The habit of this is shown in the Figure, which is reduced to about one-fourth the natural size. As the stem gets older, it becomes more elongated. Tubercles small, four-sided at the base, pointed at the top, where the spines are arranged in a star, about twenty of them on each tubercle, with two central ones, which are longer, stiffer, and much darker in colour than those on the outside; flowers small, almost hidden beneath the spines, bright carmine-rose; they are produced on the sides of the upper portion of the stem in June. There is a close resemblance between this and M.

cirrhifera, and the treatment for both should be the same. Mexico, 1835.

[Ill.u.s.tration: FIG. 62. MAMILLARIA HAAGEANA.]

M. longimamma (long-tubercled); Fig. 63.--A well-marked species in the size of its mammae, or tubercles, which are at least 1 in. long by 1/3 in.

in diameter, terete, slightly curved, and narrowed to a pointed apex, the texture being very soft and watery. Each tubercle bears a radiating tuft of about twelve spines, one central and projecting outwards; they are pale brown when old, and white when young; their length is about in. A tuft of short, white wool is developed at the base of the spines on the young mammae. The stem is seldom more than 4 in. in height, and it branches at the base when old. Flowers large and handsome, citron-yellow; the tube short, and hidden in the mammae; the petals 1 in. long, narrow, pointed, and all directed upwards; stamens numerous, short. Flowering season, early summer. Native country, Mexico. It requires greenhouse treatment, or it may be placed in a sunny frame out of doors during summer. It is not easily multiplied from seeds, but is free in the production of offsets from the base of the stem.

[Ill.u.s.tration: FIG. 63. MAMILLARIA LONGIMAMMA.]

M. macromeris (large-flowered); Fig. 64.--Stem about 4 in. high, naked at the base, woody and wrinkled when old. Tubercles as in M. longimamma, but with curving radial spines, like needles, often 2 in. in length, white or rose-tinted when young, almost black when old. Flowers from the centre of the stem, 3 in. long, and about the same in width; the petals regular and spreading, as in the Ox-eye daisy; stamens numerous, short, forming a disk; colour carmine, almost purple just before fading.

Flowering season, August. Native of Mexico, where it is found in loose, sand on hillocks, generally about the roots of Acacias. It is one of the most beautiful of all Mamillarias; but it is, as yet, rare in collections. It requires the same treatment as M. longimamma, except that, owing to the woody nature of its rootstock, and its long, tap-like roots, it should be planted in pans instead of pots, using a compost of rough loam, mixed with lumps of broken brick or limestone.

[Ill.u.s.tration: FIG. 64. MAMILLARIA MACROMERIS.]

M. macrothele (large-nippled); Bot. Mag. 3634, as M. Lehmanni.--This belongs to the same group as M. cirrhifera, but is distinguished by its large mammae, which are four-angled at the base, in. long, narrowed to a point, upon which is a tuft of wool and a cl.u.s.ter of about eight spines, in. long, spreading, reddish-brown in colour, the central one being almost black, 1 in. long, and pointing downwards. In the axils of the mammae are tufts of white wool. Flowers on the top of the stern, erect, spreading, about 1 in. across when expanded; the petals overlapping, and pale yellow; the stamens red at the base, arranged in a dense cl.u.s.ter, and the rays of the stigma spreading over them. Flowering time, early summer. Native country, Mexico, on prairie lands, at high elevations. This species is almost hardy in the warmer parts of this country, suffering from damp rather than frost in winter. The stem is not particularly handsome, but the flowers are large and bright, and they are produced annually by plants which are grown in a cool, well-aired greenhouse or frame, with the sun shining on them all day.

M. micromeris (small-flowered); Fig. 65.--A small, cushion-like plant, with a stem never more than 1 in. across by about 1 in. in height, so that it has the appearance of a small, flattened ball, with a raised, disk-like portion on the top. The mammae are very small, and they are completely hidden by the numerous fine, white, silky spines and wool which spring in tufts from the apex of each mamma, and interlace so as to form a spider-web-like net all over the stem. The flowers are small, and they spring from the centre of the disk-like top of the stern; they are composed of from three to five sepals, and five petals, which are whitish or pink, and measure about in. across when open. Native country, Mexico, where it is found only in naked places on mountain tops or sides where limestone is plentiful. It requires much care under cultivation, water in excess being fatal to it, and a soil of the wrong sort soon killing all its roots. It is cultivated at Kew in a small pot, in a mixture of loam and lime rubbish, and grown in a warm greenhouse.

[Ill.u.s.tration: FIG. 65. MAMILLARIA MICROMERIS.]

M. multiceps (many-branched).--Stem short, with numerous branches, which again push forth other branches, so that a dense tuft of dumpy, globose stems is formed. The mammae are small, and arranged closely together, and they each bear a tuft of whitish wool, with a radiating cl.u.s.ter of spines, which are soft, almost hair-like in texture, the inner ones being stiffer, and coloured dull yellow. The flowers are small, and almost hidden by the spines and tubercles; they are pale yellow, with a line of red down the middle of each petal. Native country, Mexico. This plant should be grown on a shelf in a cool greenhouse--anything like a stove temperature being fatal to it. As a flowering plant it is of no value, but the compact tuft formed by its numerous stems, with their attractive spines, renders it worthy of cultivation.

M. Neumanniana (Neumann's).--This is a member of the group with angular tubercles and comparatively small flowers. It has a stem about 6 in.

high, cylindrical, the tubercles arranged spirally, their bases compressed, four or five-angled, and with a tuft of white wool in their axils. The areoles or tufts on the tops of the mammae are large, and the spines are about seven in number, in. long, and of a tawny-yellow colour. The flowers are produced near the top of the stem; they are about in. long, and rose-red in colour. Native country, Mexico. It requires the same treatment as M. cirrhifera.

M. Ottonis (Ottoni's); Fig. 66.--A very distinct and pretty plant is cultivated under the name at Kew; but there are, apparently, two different species under the same name--the one being spiny and large in the stem; the other, which is here shown, having a small, compressed stem, 3 in. across, numerous compressed tubercles, and short, hair-like spines. The flowers, which are large for the size of the plant, are white, and are developed in May and June. Native country, Mexico; introduced in 1834. It requires similar treatment to M. micromeris.

[Ill.u.s.tration: FIG. 66. MAMILLARIA OTTONIS.]

M. pectinata (comb-like); Fig. 67.--Stems globose, from 2 in. to 3 in. in diameter; the rootstock woody; the tubercles arranged in about thirteen spiral rows, swollen at the base, and bearing each a star-like tuft of about twenty-four stiff, brown, radial spines, without a central one; the length varies from in. to 1 in., and they are comb-like in their regular arrangement. When not in flower, this species bears a close resemblance to small plants of Cereus pectinatus. Flowers terminal, solitary, large, their width quite 3 in. when fully expanded; sepals reddish-green; petals rich sulphur-yellow; filaments reddish, very numerous; the flowers open at noon, and close after about two hours, even although the sun be shining full upon them. Flowering season, June to August. Native country, Mexico, on slopes of limestone hills.

Although long since known to botanists, this pretty species has only lately found its way into English gardens. It is attractive even when not in flower. It requires warm greenhouse treatment, with exposure to full sunshine; during late autumn it should have plenty of air to ripen the new growth made whilst flowering. In winter it should have a dry position near the gla.s.s.

[Ill.u.s.tration: FIG. 67. MAMILLARIA PECTINATA.]

M. ph.e.l.losperma (corky-seeded).--A pretty plant, resembling M. Grahami in all points except the seed, which, as is denoted by the name, is half enveloped in a corky covering, suggesting acorns. Stems simple, sometimes proliferous at the base, globose when young, afterwards almost cylinder or pear-shaped, 5 in. high, 2 in. in diameter; tubercles in.

long, arranged in twelve spiral rows, slightly woolly in axils. Spines radiating, in two rows, about fifty on each tubercle, the three or four central ones being hooked at the tips or sometimes straight; length, in. to 1 in. Flowers (only seen in the dried state) 1 in. long and wide.

Native of the dry gravelly hills and sand ridges in California and Colorado, and, therefore, requiring greenhouse treatment. This plant is cultivated in the Kew collection, but it has not been known to flower there. It is one of the most ornamental of the very spinous species, the radial spines being almost white, whilst the central ones are black, and look like tiny fish-hooks. A large proportion of these Mamillarias are far more interesting in the form and arrangement of their tubercles and spines than in any floral character, and it is on this account that so many which are insignificant as flowering plants are included here.

M. pulchra (handsome).--Stem globose when young and cylindrical when old, flattened at the top; height from 4 in. to 6 in.; tubercles large, egg-shaped, arranged in from eleven to thirteen spiral rows; spines in compact tufts, their bases set in whitish wool, irregular in length, and almost covering the whole of the stem. Flowers medium in size, developed near the top of the stem from the woolly axils of the tubercles; colour bright rose. Native of Mexico. Flowering season, June. Introduced in 1826. A rare kind nowadays, though one of the prettiest. It should always be grown in a warm house. It has been also called M. pulcherrima.

M. pusilla (small).--A tiny tufted plant, belonging to the group known as Thimble Cactuses. It has stems 2 in. high; short, dark green tubercles, with tufts of whitish wool in the axils; spines thin and bristle-like, twisted, nearly 1 in. long, almost hiding the stem; they are whitish, with black tips. The flowers are yellowish-white, with streaks of red. Common in Mexico. Flowering season, May. It should be grown in a frame in summer, and wintered on a shelf in a warm greenhouse. It would, no doubt, thrive in a window if kept in a sunny position and placed under a gla.s.s shade. A variety known as texana differs in being more densely clothed with spines. We have seen it grown into large clumps, covering a s.p.a.ce 1 ft. in diameter, with dozens of erect little pyramids of whitish spines.

M. pycnacantha (densely spined); Bot. Mag. 3972.--The name for this kind is rather misleading, the spines being both fewer and less conspicuous than in many other species of Mamillaria. Stem about 6 in.

high, nearly globose; tubercles--rather large, swollen, with tufts of short white wool in their axils, and stellate cl.u.s.ters of spines springing from disks of white wool on the top. The spines are in. long, slightly recurved, flattened, and pale brown. Flowers large, cl.u.s.tered on the top of the stem, about half a dozen opening together; width 2 in.; petals numerous, narrow, toothed at the tips, spreading; colour a deep sulphur-yellow, anthers orange. Native of Oaxaca, Mexico. Flowering season, July. Introduced 1840. This is a beautiful flowering plant, more like an Echinocactus than a Mamillaria. It should be grown in a warm greenhouse all the year round. Old stems develop offsets from the base, by which the species may be multiplied.

M. sanguinea (b.l.o.o.d.y); Fig. 68.--This is closely related to M. bicolor, but differs in having an unbranched stem and numerous richly-coloured flowers. The stem is stout, 6 in. high, and 4 in. through; tubercles crowded, short, bearing stellate tufts of shortish spines, and projecting longer ones, all being bristly and pale yellow, except those on the youngest tubercles, which are golden. The flowers are borne in a crowded circle on the top of the stem, just outside the cl.u.s.ter of young yellow spines, a strong plant having about forty flowers open together.

Each flower is about in. long and wide, and coloured bright crimson, with yellow anthers. Native of Mexico. Flowers in June. It should be grown along with M. bicolor. The plant figured is a young one, showing the spines much longer than is usual on mature specimens.

[Ill.u.s.tration: FIG. 68. MAMILLARIA SANGUINEA.]

M. Scheerii (Scheer's).--Stem 7 in. high, and 5 in. in diameter at the base; tubercles large, swollen, somewhat flattened, pale green, watery, woolly in the axils, the tops crowned with about a dozen brown spines, 1 in. long, one central, the others radial. Flowers terminal, erect, with several whorls of spreading, recurved petals, the lower ones tinged with crimson, the upper pale yellow, and forming a shallow cup, 2 in. across; anthers forming a compact sheaf in the centre. Flowers in summer. This distinct and very pretty species was introduced many years ago from Mexico, where it was discovered in 1845 by a Mr. Potts, to whose love for these plants we are indebted for a great many choice kinds collected and sent to England by him. It grows naturally in a red, sandy loam, and under cultivation requires warm-house treatment, except during the autumn, when it may be placed in a frame and exposed to full sunshine and plenty of air.

M. Schelhasii (Schelhas').--A pretty little tufted kind, its habit and size being shown in Fig. 69. The stem produces offsets freely at the base, which grow into full-sized stems, and develop young ones, till a compact cushion is formed. Tubercles closely arranged, cylindrical, shining green, with fifteen to twenty radial, white, hair-like spines, in. long, and three inner ones, which are thicker, purplish in colour, usually only one being hooked. Flowers white, with a line of rose down the middle of each petal, in. across. Flowering season, beginning of summer. Native of Mexico. It may be grown out of doors in a sunny position in summer, and wintered on a shelf in a greenhouse.

[Ill.u.s.tration: FIG. 69. MAMILLARIA SCHELHASII.]

M. Schiedeana (Schiede's).--Stem globose, 3 in. to 5 in. high, thickly clothed with long, narrow, pointed tubercles, the bases of which are set in white wool, whilst the apices are crowned with tiny stars of white silky spines; more like the pappus of a Composite than the spines usually found on Cactuses. A healthy plant has a very pretty and silky appearance which cannot well be described. The flowers are small and unattractive; they are succeeded by the red fruits, which remain on the plant a long time, and add to its beauty. Native country, Mexico.

Introduced 1838. Should be grown in a greenhouse where frost is excluded, and where there is plenty of sunlight at all times. It is easily increased, either from seeds or by means of the offsets developed at the base of old stems.

M. semperviva (ever-living); Fig. 70.--Stem pear-shaped, 3 in. wide, the top slightly depressed. Tubercles conical, in. long, their bases set in a cushion of white wool, their tips bearing tiny tufts of wool, and four small spines, which fall away on the tubercles becoming ripe, leaving two short, diverging, central spines. Flowers small, not ornamental, and scantily developed near the outside of the top. Native of Mexico; in meadows and thickets near Zimapan, at 5000 ft. elevation. It thrives with us when grown in a frame in summer, and wintered in a cool greenhouse or frame.

[Ill.u.s.tration: FIG. 70. MAMILLARIA SEMPERVIVA.]

M. senilis (h.o.a.ry).--Stem about 3 in. high, spherical, unbranched, except when very old, when it becomes proliferous at the base; tubercles crowded, small, arranged spirally, and crowned with cl.u.s.ters of long, radiating spines, which are almost white, hair-like, and become thickly interwoven, as in the Old Man Cactus (Pilocereus senilis). The central spine is black, and hooked at the tip. Flowers on the top of the stem, near the centre; the petals toothed, spreading, and forming a deep cup, with a cl.u.s.ter of tall stamens standing erect in the middle; colour bright scarlet. The flowers, which appear in summer, remain open about eight hours. Native country unknown; cultivated in France in 1845. This plant is difficult to preserve in health, the best method being that of grafting it on to a short Cereus, or a robust kind of Mamillaria, such as M. cirrhifera. It is a pretty plant at all times, even when dead, for we have seen plants of it preserve the appearance of live specimens long after they have rotted and dried up in the centre, nothing remaining but the sh.e.l.l formed by the skin and silvery spines. There is a close resemblance between this species and M. Grahami.

M. stella-aurata (golden star).--This little plant obtains its name from the rich golden-yellow of its stellate cl.u.s.ters of spines, which are arranged thickly on the tips of the small, pointed tubercles. It belongs to the group called Thimble Cactuses, of which it is one of the prettiest. The stems are tufted, branching freely at the base, and rising to a height of about 2 in. Flowers small, whitish, and much less ornamental than the berry-like fruits which succeed them, and which are egg-shaped, in. long, and a deep rose-colour. M. tenuis is a variety of this, with almost white spines. Native of Mexico. Introduced 1835. May be cultivated under a bell-gla.s.s in a room window, the only danger being damp during winter, which must be carefully avoided.

M. sub-polyhedra (usually many-sided); Fig. 71.--Stem simple till it becomes old, when it develops offsets at the base, broadly cylindrical, 8 in. high, 5 in. in diameter. Tubercles four-sided at base, prism-shaped, bearing pads of white wool in the corners at the base, and crowned with tufts of from four to seven spines, usually all radial, sometimes one central. The flowers, which usually appear in May, are arranged in a zone on the top of the old stems; sepals greenish-yellow, petals bright red. Fruit 1 in. long, pear-shaped, scarlet. Native of South Mexico, at high elevations. It may be grown outside in summer, and wintered in a heated greenhouse or frame. This is a singular-looking plant, the tubercles having an appearance suggestive of carving. It is a slow grower, and requires careful attention in winter, when sometimes the roots all perish and the base of the stem rots.

[Ill.u.s.tration: FIG. 71. MAMILLARIA SUB-POLYHEDRA.]

M. sulcolanata (woolly-grooved); Fig. 72.--Stem simple when young, proliferous at the sides when old, the young plants developing from the apices of the tubercles, and not in the axils, as is usual. The tubercles are nut-shaped, large, the bases surrounded by white wool, the points bearing eight to ten rigid, brown spines, all radiating from a little pad of wool. Flowers large, nearly 2 in. across, bright yellow, poppy-scented, the spread of the petals suggesting Paris Daisies; they are freely developed on the apex of the stem in June, and on till August. Fruit egg-shaped, glaucous-green. Native country, South Mexico; introduced 1836. This charming little plant should be grown in a frame exposed to full sunshine all summer, and removed to a shelf in a warm greenhouse in winter. With such treatment it grows and flowers freely.

Grafted on to a Cereus or Opuntia it is healthier than when on its own roots.

[Ill.u.s.tration: FIG. 72. MAMILLARIA SULCOLANATA.]

M. tetracantha (four-spined); Bot. Mag. 4060.--Stem the size and shape of an ostrich's egg, thickly studded with small, conical tubercles, woolly at the base, the apices bearing each four spreading spines, in.

long, rather stout, straight, brown when young, becoming almost white with age. Flowers numerous, small, arranged as in M. sanguinea, to which and M. cirrhifera this species is closely related. They are bright rose in colour, with orange-yellow anthers, and are developed in July. Native of Mexico. Requires the same treatment as M. cirrhifera.

M. tuberculosa (tubercled).--This is a very pretty and distinct plant, of recent introduction, and easily cultivated. It has a central stem, 6 in. high by 2 in. in diameter, conical in shape, and surrounded at the base by globose branches or offsets. The tubercles are closely set in numerous spiral rows, and are in. long, rather narrow, pointed, with a crown of radial spines, very slender, hair-like, white, and in. long; central spines three or four, in. long. At the base of each tubercle is a pea-like tuft of white wool. In this kind the spines fall from the old tubercles, which are persistent, gradually hardening to a cork-like substance. The flowers are produced in the apex of the stem, and are 1 in. long and wide, daisy-like, pale purple in colour; they are succeeded by red, oval berries, which are as pretty as the flowers.

About five flowers are developed on each stem annually--May and June.

Native of Mexico, in the mountains. It thrives when grown in an ordinary greenhouse, on a shelf, in full sunshine.

M. turbinata (top-shaped); Bot. Mag. 3984.--Stem globose, depressed at top, about 3 in. in diameter, pale glaucous-green; tubercles quadrangular, flattened at the apex, and bearing, when young, from three to five erect, slender, hair-like spines, which fall off soon after the tubercles ripen, exposing little depressions or umbilica, and giving the stem a bald, pudding-like appearance, quite distinct from any other kind. Flowers from the centre of the stem, short, about 1 in. across, pale yellow, with a reddish tint outside; anthers yellow. Two or three flowers are usually expanded together in the month of June. Native country, Mexico.

M. uncinata (hooked).--Stem globose, simple, about 4 in. in diameter; tubercles closely pressed against each other at the base, where they are four-angled; in length they are in., and they are blue-green in colour.

Apex bearing four short spines, arranged crosswise, and in. long; central spine slightly longer, yellow, and hooked. The flowers are 1 in.

long and wide, erect, the tube hidden by the young mammae, amongst which they appear in May and June; they are purple in colour, a line of deeper tint running down the middle of each petal. Like all the kinds with short, angular tubercles, this species is easily managed, flowers freely and profusely, and always ripens seeds. Native of Mexico. It may be grown in a frame, or even out of doors, all through the summer, removing it to a greenhouse for the winter.

M. vetula (old).--One of the small Thimble Cactuses, its stems seldom exceeding 3 in. in height by 1 in. in diameter. Tubercles in. long, conical, with a radial crown of fine, hair-like yellow spines, in.

long, and a solitary central spine, in. in length, and coloured red.