Aloe craibii Gideon F.Sm., 2003

Smith, Gideon F., 2003, Aloe craibii Gideon F. Sm. (Asphodelaceae: Alooideae): a new species of grass aloe from the Barberton Centre of Endemism, Mpumalanga, South Africa, Bradleya 21, pp. 25-28 : 26-28

Aloe craibii Gideon F.Sm. species nova

Apparenter Aloe integra Reynolds proxima. Differt ab ea et ab speciebus ceteris generis floribus parois distincte zygomorphis constanter flaois et inflorescentia densa capitata ad cylindrica dispositis. Tepala saepe ad basin capsulae affixa remanentes. Folia margine cartilaginea dentibus parois munita.

Type: Republic of South Africa, Mpumalanga Province, 2531 (BARBERTON): in hilly country south-southeast of Barberton , (-CC), G. Condy & C. Craib 148 (holo-, PRE) .

(Compare Figure 2 .) Medium-sized, herbaceous, slow-growing, succulent, perennial, grasslike aloe, total height excluding inflorescence ± 550 mm, usually 1–6-branched from a short, stout stem, a single clump up to 300 mm in diameter. Roots fusiform, central portion 2–4 mm in diameter. Stems up to 100 mm long, 15–20 mm in diameter. Branches 80–160 mm long, erect, divergent to spreading or somewhat decumbent if growing on rocky slopes; apical half densely foliate. Leaves 6–20, not persistent when dry, distichously arranged, rarely rosulate, narrowly linear-attenuate, tapering to apex, 210–300 mm long, 20–25 mm broad at base, basally sheathing, spreading, forming medium-sized, open, distichous rosettes; upper surface distinctly and consistently canaliculate, light yellowish green, usually unspotted, rarely with few scattered white spots towards base, smooth to obsolescently striate; lower surface convex, light yellowish green, unspotted, rarely with few scattered white spots towards base; margins with a distinct ivory-coloured edge, densely armed with non-pungent, harmless, triangular teeth; teeth ivory-coloured to greenish white appearing to be an extension of the margin, teeth towards leaf bases with a reddish tinge, 1.0– 1.5 mm long towards base, becoming increasingly smaller towards tip of leaf, 1.0–2.0 mm distant, ± evenly spaced; dry leaf sap translucent. Inflorescence an unbranched raceme, 230–350 mm tall; each rosette producing a single raceme, peduncle sparsely sterile bracteate, bracts thin, papery, scarious, light brown, many-nerved, up to 30 mm long, 10 mm broad at base. Peduncle basally cylindrical to very slightly plano-convex, 180 mm long, 6–8 mm broad at base, yellowish green, dusty bloom lacking. Racemes somewhat cylindrical to capitate, very densely flowered, the flowering portion 40–100 mm long, 50–60 mm in diameter; buds erect to suberect, somewhat congested at apex, lowest open flowers suberect to horizontal, large and small racemes found in same population. Floral bracts amplexicaul around pedicel, large, thin, scarious, yellowish, with 4–7 prominent brownish nerves, 12–35 mm long. Pedicels 12–40 mm long. Flowers zygomorphic, not scented, small, 15–18 mm long, slightly stipitate at base, tubular-cymbiform, very rarely somewhat cylindrical-trigonous, usually uniformly yellow, buds yellow with darker, reddish brown tips, 5 mm in diameter in middle, buds and flowers slightly trigonously to cylindrically indented above ovary, thence enlarging towards throat and forming a very slightly open, distinctly upturned mouth; outer segments larger than inner segments, longtriangular, free for most of their length, basally fused for only 1.0–2.0 mm, free portion lacking central nerve, borders the same yellow colour as tepal blade, acute, segment margins folded lengthwise, apex slightly incurved; inner segments narrower than outer, with yellowish white border and more obtusely spreading apex, free for most of their length. Stamens 6, hypogynous; filaments cylindrically thread-like to very slightly flattened, deep yellow, 15–18 mm long, all 6 of ± equal length, not exserted; anthers small, 1.0 mm long, bright orange, versatile, included or only very slightly exserted. Ovary 10 mm long, 5 mm in diameter, light greenish yellow; style short, 5 mm long, minutely capitate; stigma small. Fruit an erect, dirty yellowish green, trilocular capsule, cylindrical, oblong, 15–20 mm long, 6–10 mm in diameter, apically truncate, dry remains of tepals persisting around fruit for a long time, dehiscing loculicidally, chartaceous to woody when dry. Seed dark greyish brown, angled, laterally compressed, with off-white wing stretching around periphery of seed, 2.5–3.0 mm long. Chromosome number: unknown.

Flowering Time: Like many species of grass aloe, A. craibii flowers in late summer and in early autumn towards the end of the rainy season, February to mid-April in the southern hemisphere, with a peak in mid-March............ Ecology and Conservation Status: The species was collected in full sun in grassland vegetation at an altitude of about 1,600 m on a southwest-facing slope in a rocky, well-drained substrate. The plants usually grow in association with Protea roupelliae Meisn . Only about 50 plants were found at the type locality, representing the full extent of the currently known populations. Although further populations may be found in time, for example in Swaziland, it would be prudent to regard the species at least currently as Critically Rare.

Eponymy: This species is named for Mr Charles Craib of Johannesburg, South Africa, who has contributed considerably to our understanding of the grass aloes, a horticulturally charming and taxonomically intriguing group of aloes.

Figures

Figure 2. Aloe craibii Gideon F.Sm. A. Inflorescence (length = 230 mm). B. Leaf (length = 240 mm). C. Upper half of post-flowering inflorescence in fruit (length = 170 mm). D. Habit (total height of plant illustrated, including inflorescence = 900 mm ). Artist: Gillian Condy.