Stenocereus

(A. Berger) Riccobono

Boll. Reale Orto Bot. Palermo 8: 253. 1909.

Etymology: Greek stenos, narrow, and Cereus, referring to the genus from which this segregate was removed
Basionym: Cereus subg. Stenocereus A. Berger Rep. (Annual) Missouri Bot. Gard. 16: 66, plate 3. 1905
Synonyms: Hertrichocereus Backeberg Machaerocereus Britton & Rose
Treatment appears in FNA Volume 4. Treatment on page 186. Mentioned on page 97, 187.

Trees or shrubs, erect, arching, or procumbent, mostly branched from base. Roots adventitious if plant procumbent. Stems unsegmented, often more narrow at branch bases and where showing growth increments, green to bluish green [or whitish from surface wax or purple-tinged from pigment], columnar, ribbed, [50–] 100–500+ × [5–] (9–) 11–18 [–20] cm; ribs 4–20, rounded, margins nearly flat to sinusoidal or strongly tuberculate, with transverse folds between areoles or not; areoles 0.5–2.5 cm apart, circular to horizontally elliptic, young hairs whitish or tan to reddish-brown, aging darker; areolar glands present or absent; cortex mucilaginous or not, mucilage throughout and slippery or restricted to sacs in outer cortex, green to white or yellowish; pith mucilaginous or not, 1–8 cm wide. Spines to 28 per areole, hemispherically arranged, initially rose to magenta, becoming darker or fading to grayish white, relatively thin and brittle to stout and very hard; radial spines to 3.5 cm; central spines usually weakly defined or absent, sometimes broad and downward pointing, to 7.5 cm. Flowers diurnal or nocturnal, produced only once on areole [or not], terminal to lateral, funnelform [to tubular]; flower tubes2–11 cm; outer tepals with dark green to purplish centers but light margins, margins entire; inner tepals white to rose-red [or yellow]; ovary globose to barrel-shaped, similar to locule shape; scales persistent, reddish or green with red tips, small, triangular; hairs and spines often present; stigma lobes 5–15, inserted or exserted; nectar chamber open. Fruits indehiscent or sometimes splitting irregularly, dark red to purplish green or green, spheric [to ovoid], 30–100 mm, fleshy to juicy [or somewhat dry], bearing deciduous spine clusters; pulp red, special pigment cells present; floral remnant persistent or deciduous. Seeds brownish black or black, oblong to subspheric with oblique hilum, 0.7–3 mm, dull or rarely glossy; testa cells convex or nearly flat, with prominent to faint, raised waxy striations or not. x = 11.

Distribution

s Ariz., Mexico, West Indies, coastal Central America, n South America, cultivated and naturalized elsewhere

Discussion

Species ca. 20 (1 in the flora).

During the nineteenth century, the ribbed columnar cacti, numbering in the hundreds, were generally classified as species of Cereus. In the early twentieth century, however, Cereus, in the broadest sense, was subdivided into many smaller and more homogeneous units, initially by N. L. Britton and J. N. Rose (1909, 1919–1923). The phylogenetic relationships of North American columnar species were clarified by studies of silica bodies in the epidermis and hypodermis covering the stems of certain Mexican species, distinctive pigment cells, called pearl cells, in the fruit pulp, and sugar-bearing oleanane triterpenes in stem tissues (A. C. Gibson and K. E. Horak 1978). Species possessing all three derived characters were removed from Lemaireocereus, Machaerocereus, Rathbunia, Hertrichocereus, Ritterocereus, and Marshallocereus and placed into the genus Stenocereus, which was further emended by removing species without the shared characters.

Several of the Central American species assigned to Stenocereus by E. F. Anderson (2001) are too poorly studied to know whether or not they have the diagnostic characters for the genus. A carefully done DNA phylogeny for all taxa with possible inclusion in Stenocereus is needed, especially to define more precisely the phylogenetic lineages and patterns of speciation (R. S. Wallace and A. C. Gibson 2002).

"broad" is not a number."thin" is not a number.

... more about "Stenocereus"
cushionlike +
circular +  and horizontally elliptic +
deciduous +  and persistent +
hourglass--shaped +
0.5 cm5 mm <br />0.005 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Arthur C. Gibson +
(A. Berger) Riccobono +
hardened +
Cereus subg. Stenocereus +
triangular +
50 cm500 mm <br />0.5 m <br /> (100 cm1,000 mm <br />1 m <br />) +
18 cm180 mm <br />0.18 m <br /> (20 cm200 mm <br />0.2 m <br />) +
100 cm1,000 mm <br />1 m <br /> (500 cm5,000 mm <br />5 m <br />) +
11 cm110 mm <br />0.11 m <br /> (18 cm180 mm <br />0.18 m <br />) +
dark green;purplish +
pointing +  and downward +
0 cm0 mm <br />0 m <br /> (7.5 cm75 mm <br />0.075 m <br />) +
proliferating +
flattened +  and cylindric +
not +  and mucilaginous +
s Ariz. +, Mexico +, West Indies +, coastal Central America +, n South America +  and cultivated and naturalized elsewhere +
not separating +
Greek stenos, narrow, and Cereus, referring to the genus from which this segregate was removed +
deciduous +  and persistent +
nocturnal +  and diurnal +
terminal +  and lateral +
2 cm20 mm <br />0.02 m <br /> (11 cm110 mm <br />0.11 m <br />) +
15 cm150 mm <br />0.15 m <br /> (30 cm300 mm <br />0.3 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (15 cm150 mm <br />0.15 m <br />) +
dark red;purplish green or green +
indehiscent +
persistent +, long +  and deciduous +
spheric +
3 cm30 mm <br />0.03 m <br /> (10 cm100 mm <br />0.1 m <br />) +
fleshy +  and juicy +
darker +, tan +  and reddish-brown +
aging +  and young +
deciduous +  and persistent +
rudimentary +
flat +  and terete +
nearly +  and microscopic +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
tuberculate +
fluted;spheric;depressed-spheric or club-shaped +
tuberculate +
nearly flat +  and sinusoidal +
restricted to sacs in outer cortex +  and slippery +
globose +  and barrel-shaped +
deciduous +  and persistent +
not +  and mucilaginous +
1 cm10 mm <br />0.01 m <br /> (8 cm80 mm <br />0.08 m <br />) +
ridgelike +  and nipple--shaped +
Boll. Reale Orto Bot. Palermo +
cornejo1997a +, gibson1978a +, gibson1988a +, gibson1990a +, parker1987a +  and parker1987b +
rounded +
adventitious +
green +  and reddish +
persistent +
triangular +
arillate +  and strophiolate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
glossy +  and dull +
oblong;subspheric +
radial +  and arranged +
fading +  and grayish white +
deciduous +
brittle +  and stout +
annulate-ridged +, hairlike +, daggerlike +, subulate +  and acicular +
decurrent +
unsegmented +
segmented +
succulent +
exserted +  and inserted +
tuberculate +
Hertrichocereus +  and Machaerocereus +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Stenocereus +
Cactaceae subfam. Cactoideae +
dull +  and glossy +
shrub +, procumbent +  and tree +
epiphytic;epiphytic;epiphytic +
arching +  and erect +
barrel-shaped +  and spheric +